Plugin with id 'com.google.gms.google-services' not found. root build.gradle에 dependency 부분에 classpath 'com.google.gms:google-services:4.3.2' 를 추가한다. Manifest merger failed : uses-sdk:minSdkVersion 15 cannot be smaller than version 16 declared in library [com.google.firebase:firebase-iid:19.0.0] ...\AndroidManifest.xml as uses-sdk:minSdkVersion 15 cannot be smaller than version 16 declared in li..