Use released version of messaging.

Author: yifanyang

smoke-tests/build.gradle

@@ -69,7 +69,8 @@ dependencies {
   implementation "com.google.firebase:firebase-firestore"
   implementation "com.google.firebase:firebase-functions"
   implementation "com.google.firebase:firebase-inappmessaging"
-  implementation "com.google.firebase:firebase-messaging"
+  // TODO(yifany): Remove version after messaging is up to date
+  implementation "com.google.firebase:firebase-messaging:21.0.0"
   implementation "com.google.firebase:firebase-ml-vision"
   implementation "com.google.firebase:firebase-perf"
   implementation "com.google.firebase:firebase-storage"