Summary:
public
This diff adds the ability to specify a custom React component (aka view) to be displayed as a MapView pin.
This makes it possible to use remote images (using an <Image/> component), or text (using a <Text/> component), or anything else.
One consequence of this is that MapView can no longer support arbitrary subviews. To place views in front the map, add them to a separate container view.
Reviewed By: tadeuzagallo
Differential Revision: D2764790
fb-gh-sync-id: e16b44e866c2d76c76b0cb35ef9eefbfc68d6719