Android app does not connect to Firebase

Question

I\'m developing android app using Firebase GMS service.
I tried to follow their tutorials, i made project as they said, downloaded the json files.

But when I

Answer 1

Make sure that your app/build.gradle doesn't have obsolete dependencies and declaration. Mine the problem was with using

dataBinding {
    enabled = true
}

instead of

buildFeatures{
        dataBinding = true
    }