FirebaseUI Auth P1

if (FirebaseAuth.getInstance().currentUser == null) {
    // user needs to authenticate
    val providers = arrayListOf(
        AuthUI.IdpConfig.GoogleBuilder().build()
    )

    startActivityForResult(
        AuthUI.getInstance()
            .createSignInIntentBuilder()
            .setAvailableProviders(providers)
            .build(),
        RQ_FIREBASE_AUTH
    )
} else {
    //user is authenticated
}