Fix paths for release.yml

Author: jonthysell

.ado/release.yml

@@ -50,7 +50,7 @@ extends:
           displayName: NuGet push (react-native)
           inputs:
             script: nuget.exe push *.nupkg -ApiKey AzureArtifacts -Source https://pkgs.dev.azure.com/ms/_packaging/react-native/nuget/v3/index.json -NonInteractive -Verbosity Detailed -SkipDuplicate -NoSymbols
-            workingDirectory: $(System.DefaultWorkingDirectory)/Publish/ReactWindows-final-nuget
+            workingDirectory: $(Pipeline.Workspace)/ReactWindows-final-nuget
     - stage: PushToPublicAdoStage
       displayName: ADO - react-native-public
       jobs:
@@ -75,7 +75,7 @@ extends:
           displayName: NuGet push (react-native-public)
           inputs:
             script: nuget.exe push *.nupkg -ApiKey AzureArtifacts -Source https://pkgs.dev.azure.com/ms/react-native/_packaging/react-native-public/nuget/v3/index.json -NonInteractive -Verbosity Detailed -SkipDuplicate -NoSymbols
-            workingDirectory: $(System.DefaultWorkingDirectory)/Publish/ReactWindows-final-nuget
+            workingDirectory: $(Pipeline.Workspace)/ReactWindows-final-nuget
     - stage: PushToNuGetStage
       displayName: nuget.org - Push nuget packages
       variables:
@@ -98,9 +98,9 @@ extends:
           displayName: NuGet SetApiKey (nuget.org)
           inputs:
             script: nuget.exe SetApiKey $(nugetorg-apiKey-push)
-            workingDirectory: $(System.DefaultWorkingDirectory)/Publish/ReactWindows-final-nuget
+            workingDirectory: $(Pipeline.Workspace)/ReactWindows-final-nuget
         - task: CmdLine@2
           displayName: NuGet push (nuget.org)
           inputs:
             script: nuget.exe push .\Microsoft.ReactNative.*.nupkg -Source https://api.nuget.org/v3/index.json -SkipDuplicate -NoSymbol -NonInteractive -Verbosity Detailed
-            workingDirectory: $(System.DefaultWorkingDirectory)/Publish/ReactWindows-final-nuget
+            workingDirectory: $(Pipeline.Workspace)/ReactWindows-final-nuget