Add Google Services Gradle plugin integration to withHuaweiPush.js to enable Firebase initialization alongside Huawei Push. This includes: - Adding google-services classpath dependency for buildscript - Applying com.google.gms.google-services plugin after React plugin - Copying google-services.json to android/app/ for runtime initialization Without these changes, Firebase initialization fails at runtime with "default FirebaseApp is not initialized" when google-services.json is configured in app.json.