I have checked my app build.gradle file and these are the only lines that are related to firebase in them
/***
* Firebase
*/
implementation \'com.google.f
Remove this from App level gradle
implementation 'com.google.android.gms:play-services-maps:15.0.0'
and then try these versions
compile 'com.google.firebase:firebase-core:11.8.0'
compile 'com.google.firebase:firebase-messaging:11.8.0'
compile 'com.google.firebase:firebase-database:11.8.0'
compile 'com.google.firebase:firebase-auth:11.8.0'
this one worked for me... tanx