How to migrate from GCM to FCM?
This guide will show you how to migrate from use of GCM (Google Cloud Messages) to FCM (Firebase Cloud Messages).
1.) go to https://console.firebase.google.com/
2.) Click -> or Import a google project
![How to migrate from GCM to FCM](1.png)
3.) Click -> Add Firebase to you Android app
![How to migrate from GCM to FCM](2.png)
4.) enter your app package name and press -> Add app
![How to migrate from GCM to FCM](3.png)
5.) download and add file "google-services.json" to you app
![How to migrate from GCM to FCM](4.png)
6.) Add a lines in your build.gradle files (two different files - be careful)
![How to migrate from GCM to FCM](5.png)