Transparent circle around blue "my location" dot does not represent GPS accuracy

[gmaclennan]

The blue dot representing the users location is surrounded by a large transparent blue circle. In other mapping apps this transparent circle represents location (GPS) accuracy, but in the current implementation the circle is just a fixed size.

This will be fixed by using "native location" https://github.com/react-native-mapbox-gl/maps/pull/825 in mapbox-gl/maps, but the current implementation in v8.1.0-rc.2 throws an error sometimes, so it does not seem quite ready.