Include explicitly protobuf dependency on testing

Author: rlazo

firebase-firestore/firebase-firestore.gradle

@@ -152,6 +152,7 @@ dependencies {
 
     testImplementation project(':firebase-database-collection')
     testImplementation project(':firebase-firestore')
+    testProtobuf("com.google.api.grpc:proto-google-common-protos:1.18.0")
     testImplementation libs.androidx.test.core
     testImplementation 'com.fasterxml.jackson.core:jackson-databind:2.9.8'
     testImplementation 'com.google.android.gms:play-services-tasks:18.0.1'

firebase-firestore/src/main/java/com/google/firebase/firestore/remote/TestingHooks.java

@@ -16,6 +16,7 @@
 
 import static com.google.firebase.firestore.util.Preconditions.checkNotNull;
 
+import android.annotation.SuppressLint;
 import androidx.annotation.AnyThread;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
@@ -34,6 +35,7 @@
  *
  * <p>Do not use this class except for testing purposes.
  */
+@SuppressLint("SupportAnnotationUsage")
 @VisibleForTesting
 final class TestingHooks {