fix gradle build issues

Author: Robert von Massow

stub/src/test/java/io/grpc/kotlin/AbstractCallsTest.kt

@@ -149,14 +149,16 @@ abstract class AbstractCallsTest {
   }
 
   /** Generates a channel to a Greeter server with the specified implementation. */
-  fun makeChannel(impl: BindableService): ManagedChannel {
+  fun makeChannel(impl: BindableService, vararg interceptors: ServerInterceptor): ManagedChannel {
     val serverName = InProcessServerBuilder.generateName()
 
     grpcCleanup.register(
       InProcessServerBuilder.forName(serverName)
         .run { this as ServerBuilder<*> } // workaround b/123879662
         .executor(executor)
-        .addService(impl)
+        .addService(
+          ServerInterceptors.intercept(impl, *interceptors)
+        )
         .build()
         .start()
     )
@@ -188,6 +190,9 @@ abstract class AbstractCallsTest {
       }
     )
 
+ fun makeChannel(impl: ServerServiceDefinition?, vararg interceptors: ServerInterceptor): ManagedChannel =
+   makeChannel(BindableService { impl }, *interceptors)
+
   fun <R> runBlocking(block: suspend CoroutineScope.() -> R): Unit =
     kotlinx.coroutines.runBlocking(context) {
       block()

stub/src/test/java/io/grpc/kotlin/CoroutineContextServerInterceptorTest.kt

@@ -16,7 +16,6 @@ import kotlin.coroutines.coroutineContext
 import io.grpc.Metadata as GrpcMetadata
 
 /** Tests for [CoroutineContextServerInterceptor]. */
-@RunWith(JUnit4::class) /* inserted by Copybara: */ @com.google.testing.testsize.MediumTest
 class CoroutineContextServerInterceptorTest : AbstractCallsTest() {
   class ArbitraryContextElement(val message: String = "") : CoroutineContext.Element {
     companion object Key : CoroutineContext.Key<ArbitraryContextElement>