Comment cloud message for Android

[buhe]

Someone comment cloud message for Android ...

https://github.com/fullstackreact/react-native-firestack/blob/master/android/src/main/java/io/fullstack/firestack/FirestackPackage.java#L33

[Salakar]

@buhe I believe that's because there's an issue with the messaging module, but there are alternatives you can use that have a full FCM/messaging implementation.