I am following this link to integrate Google sign-in in my android app.https://developers.google.com/identity/sign-in/android/start-integrating As given in last step on the
I had a similar issue/error.. fixed it by moving apply plugin: 'com.google.gms.google-services' to the end of app level gradle file.
apply plugin: 'com.google.gms.google-services'
And updated the version of gms:play-services and gms:play-services auth
gms:play-services
gms:play-services auth