title: MapView remains empty Android
body: <p>I have a mapView and want to show marker on this mapView. 
  The problem is that the mapView  remains empty. 
  In debug modus, one has different Google Maps SDK API Key, I know this.
  I tried release and debug modus with the correct API keys and the mapView is still empty.</p>
  
  <p>THis is my code:</p>
  
  <pre><code>public class NavToLocation extends AppCompatActivity implements OnMapReadyCallback {
      TextView textViewlocation
      Bundle bundle;
  
      private GoogleMap mMap;
      MapView mapFragment;
  
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.navigation_to_location);
          textViewlocation = findViewById(R.id.textViewAddress);
  
  
  mapFragment = findViewById(R.id.mapView3);
          mapFragment.onCreate(savedInstanceState);
  
          mapFragment.getMapAsync(NavToLocation.this);
  
  
          bundle = getIntent().getExtras();
  
          String message = bundle.getString("message");
          setTextAddress(message);
  
  
  
  
     }
  
  
      public void setTextAddress(String text) {
          textViewlocation.setText(text);
      }
  
  
  
      @Override
      public void onMapReady(GoogleMap googleMap) {
          mMap = googleMap;
          LatLng sydney = new LatLng(-34, 151);
          mMap.addMarker(new MarkerOptions().position(sydney).title("Marker in Sydney"));
          mMap.moveCamera(CameraUpdateFactory.newLatLng(sydney));
          mapFragment.onResume();
      }
  }
  </code></pre>