hotfix PROVIDER_GOOGLE

Author: alvelig

index.js

@@ -10,5 +10,7 @@ export { default as Overlay } from './lib/components/MapOverlay.js';
 export { default as Callout } from './lib/components/MapCallout.js';
 export { default as AnimatedRegion } from './lib/components/AnimatedRegion.js';
 export { Animated, ProviderPropType, MAP_TYPES } from './lib/components/MapView.js';
+export const PROVIDER_GOOGLE = MapView.PROVIDER_GOOGLE;
+export const PROVIDER_DEFAULT = MapView.PROVIDER_DEFAULT;
 
 export default MapView;