Merge pull request #3006 from nextcloud/mario-firebase-core-removal

Remove Firebase-core from the build

build.gradle

@@ -30,6 +30,7 @@ apply plugin: 'findbugs'
 apply plugin: 'jacoco-android'
 
 configurations.all {
+    exclude group: 'com.google.firebase', module: 'firebase-core'
     // check for updates every build
     resolutionStrategy.cacheChangingModulesFor 0, 'seconds'
 }