Remove addMarkerView in favour of addMarker

[tobrun]

Marker views landed with #3276. Currently the API is exposed as:

MarkerView addMarkerView(MarkerViewOptions options)
Marker addMarker(MarkerOptions options);

I prefer exposing one method instead:

MarkerView addMarker(MarkerViewOptions options)
Marker addMarker(MarkerOptions options);

While above is no problem,
the method for adding a List gives: both methods have same erasure

List<Marker> addMarkers(List<? extends BaseMarkerOptions> markerOptionsList);
List<MarkerView> addMarkers(@NonNull List<? extends BaseMarkerViewOptions> markerOptionsList)

[tobrun]

I have decided to go for the simple addMarker for both GL based markers as View based markers. As a result I'm not going to expose a List<MarkerView> addMarkers(@NonNull List<? extends BaseMarkerViewOptions> markerOptionsList).