App crash when form loaded in edit mode contains unanswered repeat group item

[Rkareko]

Describe the bug
When a form containing a repeat group is saved without populating the items withing the repeat group, opening the form in edit mode results in an app crash.

The following exception is thrown: -

AndroidRuntime          com.google.android.fhir.demo         E  FATAL EXCEPTION: main
                                                                                                    Process: com.google.android.fhir.demo, PID: 4641
                                                                                                    java.lang.IllegalArgumentException: Failed requirement.
                                                                                                    	at com.google.android.fhir.datacapture.extensions.MoreQuestionnairesKt.forEachItemPair(MoreQuestionnaires.kt:202)
                                                                                                    	at com.google.android.fhir.datacapture.extensions.MoreQuestionnairesKt.forEachItemPair(MoreQuestionnaires.kt:226)
                                                                                                    	at com.google.android.fhir.datacapture.extensions.MoreQuestionnairesKt.forEachItemPair(MoreQuestionnaires.kt:217)
                                                                                                    	at com.google.android.fhir.datacapture.extensions.MoreQuestionnairesKt.forEachItemPair(MoreQuestionnaires.kt:190)
                                                                                                    	at com.google.android.fhir.datacapture.QuestionnaireViewModel.initializeCalculatedExpressions(QuestionnaireViewModel.kt:612)
                                                                                                    	at com.google.android.fhir.datacapture.QuestionnaireViewModel.access$initializeCalculatedExpressions(QuestionnaireViewModel.kt:85)
                                                                                                    	at com.google.android.fhir.datacapture.QuestionnaireViewModel$questionnaireStateFlow$2.invokeSuspend(QuestionnaireViewModel.kt:593)
                                                                                                    	at com.google.android.fhir.datacapture.QuestionnaireViewModel$questionnaireStateFlow$2.invoke(Unknown Source:8)
                                                                                                    	at com.google.android.fhir.datacapture.QuestionnaireViewModel$questionnaireStateFlow$2.invoke(Unknown Source:4)
                                                                                                    	at kotlinx.coroutines.flow.FlowKt__TransformKt$onEach$$inlined$unsafeTransform$1$2.emit(Emitters.kt:219)
                                                                                                    	at kotlinx.coroutines.flow.FlowKt__TransformKt$withIndex$1$1.emit(Transform.kt:67)
                                                                                                    	at kotlinx.coroutines.flow.FlowKt__ZipKt$combine$$inlined$combineUnsafe$FlowKt__ZipKt$1$2.invokeSuspend(Zip.kt:258)
                                                                                                    	at kotlinx.coroutines.flow.FlowKt__ZipKt$combine$$inlined$combineUnsafe$FlowKt__ZipKt$1$2.invoke(Unknown Source:13)
                                                                                                    	at kotlinx.coroutines.flow.FlowKt__ZipKt$combine$$inlined$combineUnsafe$FlowKt__ZipKt$1$2.invoke(Unknown Source:6)
                                                                                                    	at kotlinx.coroutines.flow.internal.CombineKt$combineInternal$2.invokeSuspend(Combine.kt:73)
                                                                                                    	at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
                                                                                                    	at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:104)
                                                                                                    	at kotlinx.coroutines.EventLoop.processUnconfinedEvent(EventLoop.common.kt:65)
                                                                                                    	at kotlinx.coroutines.DispatchedTaskKt.resumeUnconfined(DispatchedTask.kt:241)
                                                                                                    	at kotlinx.coroutines.DispatchedTaskKt.dispatch(DispatchedTask.kt:159)
                                                                                                    	at kotlinx.coroutines.CancellableContinuationImpl.dispatchResume(CancellableContinuationImpl.kt:466)
                                                                                                    	at kotlinx.coroutines.CancellableContinuationImpl.resumeImpl(CancellableContinuationImpl.kt:500)
                                                                                                    	at kotlinx.coroutines.CancellableContinuationImpl.resumeImpl$default(CancellableContinuationImpl.kt:489)
                                                                                                    	at kotlinx.coroutines.CancellableContinuationImpl.resumeWith(CancellableContinuationImpl.kt:364)
                                                                                                    	at kotlinx.coroutines.flow.SharedFlowImpl.tryEmit(SharedFlow.kt:409)
                                                                                                    	at kotlinx.coroutines.flow.internal.SubscriptionCountStateFlow.increment(AbstractSharedFlow.kt:125)
                                                                                                    	at kotlinx.coroutines.flow.internal.AbstractSharedFlow.allocateSlot(AbstractSharedFlow.kt:64)
                                                                                                    	at kotlinx.coroutines.flow.StateFlowImpl.collect(StateFlow.kt:382)
                                                                                                    	at kotlinx.coroutines.flow.ReadonlyStateFlow.collect(Unknown Source:2)
                                                                                                    	at com.google.android.fhir.datacapture.QuestionnaireFragment$onViewCreated$3.invokeSuspend(QuestionnaireFragment.kt:158)
                                                                                                    	at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
                                                                                                    	at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:104)
                                                                                                    	at androidx.lifecycle.DispatchQueue.drainQueue(DispatchQueue.kt:74)
                                                                                                    	at androidx.lifecycle.DispatchQueue.resume(DispatchQueue.kt:53)
                                                                                                    	at androidx.lifecycle.LifecycleController.observer$lambda$0(LifecycleController.kt:40)
                                                                                                    	at androidx.lifecycle.LifecycleController.$r8$lambda$oWRpCg8vH8nSBgktHTqCr-ANl8M(Unknown Source:0)
                                                                                                    	at androidx.lifecycle.LifecycleController$$ExternalSyntheticLambda0.onStateChanged(D8$$SyntheticClass:0)
                                                                                                    	at androidx.lifecycle.LifecycleRegistry$ObserverWithState.dispatchEvent(LifecycleRegistry.kt:314)
                                                                                                    	at androidx.lifecycle.LifecycleRegistry.forwardPass(LifecycleRegistry.kt:251)
                                                                                                    	at androidx.lifecycle.LifecycleRegistry.sync(LifecycleRegistry.kt:287)

Component
SDC library

To Reproduce
Steps to reproduce the behavior:

1. On the demo app new patient registration form, change the Client info group into a repeat group by adding "repeats": "true". The Client info repeat group contains the first and family name fields.
2. Run the demo app and register a new patient. Do not click on the +Add button under the Client info title i.e do not add the first or family name.
3. Fill in the rest of the fields and save the form
4. Go to the patient list and open the card for the patient
5. Click on the edit symbol that appears on the top right section of the screen.
6. App crashes

Expected behavior
App should not crash when the form is opened in edit mode.

Screenshots
If applicable, add screenshots to help explain your problem.
Add patient form with the Client Info as a repeat group item

Smartphone (please complete the following information):

• Device: Pixel 2 emulator
• Android version: Android 11
• Build number: RSR1.201013.00
• Version 30

Additional context
It seems that the addMissingResponseItems function that is called in the QuestionnaireViewModel.init function does not handle repeat groups.

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