Может кто тут ответит?
https://ru.stackoverflow.com/questions/1074806/%d0%9a%d0%b0%d0%ba-%d0%bf%d0%be%d0%bb%d1%83%d1%87%d0%b8%d1%82%d1%8c-%d0%bc%d0%be%d0%b4%d0%b5%d0%bb%d1%8c-%d0%b8%d0%b7-%d1%84%d1%80%d0%b0%d0%b3%d0%bc%d0%b5%d0%bd%d1%82%d0%b0-%d0%b2-fcm-%d1%81%d0%b5%d1%80%d0%b2%d0%b8%d1%81-android