dataconnect: GrpcMetadataIntegrationTest.kt: Fix race condition waiting for auth/appcheck to be ready

[dconeybe]

This PR fixes a race condition in GrpcMetadataIntegrationTest.kt where the query/mutation may be sent before the Auth and/or AppCheck provider was registered, which is done asynchronously. This race condition resulted in flaky tests. We may want to expose this functionality to customers if they run into similar issues.

For the record, the test case failures look like this:

failed: executeQueryShouldSendAppCheckMetadataWhenAppCheckIsEnabled(com.google.firebase.dataconnect.GrpcMetadataIntegrationTest)
java.lang.AssertionError: key=Key{name='x-firebase-appcheck'}, metadata=Metadata(user-agent=grpc-java-okhttp/1.62.2,content-type=application/grpc,te=trailers,x-goog-request-params=location=TestLocationr24xs74t3s&frontend=data,x-goog-api-client=gl-kotlin/1.8.22 gl-android/35 fire/16.0.0-beta03 grpc/,x-firebase-gmpid=1:12345678901:android:1234567890abcdef123456,grpc-accept-encoding=gzip)
Expected "7gwvj8c4xy" but actual was null
 	at com.google.firebase.dataconnect.GrpcMetadataIntegrationTest.verifyMetadataContains(GrpcMetadataIntegrationTest.kt:292)

failed: executeMutationShouldSendAuthMetadataWhenLoggedIn(com.google.firebase.dataconnect.GrpcMetadataIntegrationTest)
java.lang.AssertionError: key=Key{name='x-firebase-auth-token'}, metadata=Metadata(user-agent=grpc-java-okhttp/1.62.2,content-type=application/grpc,te=trailers,x-goog-request-params=location=TestLocationxbjfp54tnt&frontend=data,x-goog-api-client=gl-kotlin/1.8.22 gl-android/35 fire/16.0.0-beta03 grpc/,x-firebase-gmpid=1:12345678901:android:1234567890abcdef123456,x-firebase-appcheck=eyJlcnJvciI6IlVOS05PV05fRVJST1IifQ==,grpc-accept-encoding=gzip)
Expected value to not be null, but was null.
	at com.google.firebase.dataconnect.GrpcMetadataIntegrationTest.verifyMetadataContains(GrpcMetadataIntegrationTest.kt:290)

failed: executeQueryShouldNotSendAuthMetadataAfterLogout(com.google.firebase.dataconnect.GrpcMetadataIntegrationTest)
java.lang.AssertionError: key=Key{name='x-firebase-auth-token'}, metadata=Metadata(user-agent=grpc-java-okhttp/1.62.2,content-type=application/grpc,te=trailers,x-goog-request-params=location=TestLocationjf5zs743ev&frontend=data,x-goog-api-client=gl-kotlin/1.8.22 gl-android/35 fire/16.0.0-beta03 grpc/,x-firebase-gmpid=1:12345678901:android:1234567890abcdef123456,grpc-accept-encoding=gzip)
Expected value to not be null, but was null.
	at com.google.firebase.dataconnect.GrpcMetadataIntegrationTest.verifyMetadataContains(GrpcMetadataIntegrationTest.kt:290)

Note: This PR introduced a race condition that was fixed a few commits later in #6448

[github-actions]

📝 PRs merging into main branch

Our main branch should always be in a releasable state. If you are working on a larger change, or if you don't want this change to see the light of the day just yet, consider using a feature branch first, and only merge into the main branch when the code complete and ready to be released.

[github-actions]

📝 PRs merging into main branch

Our main branch should always be in a releasable state. If you are working on a larger change, or if you don't want this change to see the light of the day just yet, consider using a feature branch first, and only merge into the main branch when the code complete and ready to be released.

[github-actions]

Vertex AI Mock Responses Check ⚠️

A newer major version of the mock responses for Vertex AI unit tests is available. update_responses.sh should be updated to clone the latest version of the responses: v5.2

[github-actions]

Test Results

   54 files   -   454     54 suites   - 454   2m 10s ⏱️ - 10m 41s
  517 tests  - 2 418    516 ✅  - 2 400  1 💤  - 18  0 ❌ ±0 
1 034 runs   - 4 936  1 032 ✅  - 4 900  2 💤  - 36  0 ❌ ±0 

Results for commit 82d9331. ± Comparison against base commit 4100ebf.

This pull request removes 2420 and adds 2 tests. Note that renamed tests count towards both.

com.google.firebase.CoroutinesPlayServicesTests ‑ Task#await() resolves to the same result as Task#getResult()
com.google.firebase.CoroutinesPlayServicesTests ‑ Task#await() throws an Exception for failing Tasks
com.google.firebase.DataCollectionPostNDefaultEnabledTest ‑ isDataCollectionDefaultEnabled_shouldDefaultToTrue
com.google.firebase.DataCollectionPostNDefaultEnabledTest ‑ isDataCollectionDefaultEnabled_whenPrefsFalse_shouldReturnFalse
com.google.firebase.DataCollectionPostNDefaultEnabledTest ‑ isDataCollectionDefaultEnabled_whenPrefsTrue_shouldReturnTrue
com.google.firebase.DataCollectionPostNDefaultEnabledTest ‑ setDataCollectionDefaultEnabledFalse_shouldUpdateSharedPrefs
com.google.firebase.DataCollectionPostNDefaultEnabledTest ‑ setDataCollectionDefaultEnabled_shouldNotAffectOtherFirebaseAppInstances
com.google.firebase.DataCollectionPreNDefaultEnabledTest ‑ isDataCollectionDefaultEnabled_shouldDefaultToTrue
com.google.firebase.DataCollectionPreNDefaultEnabledTest ‑ isDataCollectionDefaultEnabled_whenPrefsFalse_shouldReturnFalse
com.google.firebase.DataCollectionPreNDefaultEnabledTest ‑ isDataCollectionDefaultEnabled_whenPrefsTrue_shouldReturnTrue
…

com.google.firebase.dataconnect.core.FirebaseDataConnectImplUnitTest ‑ awaitAppCheckReady() should return once the provider is available
com.google.firebase.dataconnect.core.FirebaseDataConnectImplUnitTest ‑ awaitAuthReady() should return once the provider is available