How to create a trigger to detect if the map service is available with android

In my project I have a Location Service with others Google Services Api related with Maps, and I need to create something to manager if the Map service is available or not in runtime, I'm already handling the lifecycle in parts just to show the user that he is not connected by :

@Override
protected void onRestart() {
    super.onRestart();
    if(mGoogleApiClient != null && mGoogleApiClient.isConnected()){
        startLocationUpdate();
    }
    Toast.makeText(this, "The map service is not Connected!", Toast.LENGTH_SHORT).show();

}

But if the connection returns or sometimes when I reboot my Android Device and try to open my App i have a Exception because the GoogleApiClient is null, so basically, if this GoogleApiClient object is null the app needs to "wait" until the connection comes back so it could tracking the user.

I was thinking of use Services, but i didn't want something in background testing if the connection is available, too much process on background, there's any other way to detect this ? Thanks!