Apply this in build.gradle(Project: your project name) where tools.build:gradle is present and not in build.gradle(Module: app)
buildscript {
repositories {
jcenter()
}
dependencies {
classpath 'com.android.tools.build:gradle:2.1.2'
classpath 'com.google.gms:google-services:3.0.0'
}
}
In build.gradle(Module: app) outside dependencies add this:
apply plugin: 'com.google.gms.google-services'
