Add heading to the onUserLocationChange listener (#3045)

Author: kuzkokov

index.d.ts

@@ -125,6 +125,7 @@ declare module "react-native-maps" {
         timestamp: number;
         accuracy: number;
         speed: number;
+        heading: number;
         isFromMockProvider: boolean;
       };
     };

lib/android/src/main/java/com/airbnb/android/react/maps/AirMapView.java

@@ -230,6 +230,7 @@ public void onMyLocationChange(Location location){
         coordinate.putDouble("timestamp", location.getTime());
         coordinate.putDouble("accuracy", location.getAccuracy());
         coordinate.putDouble("speed", location.getSpeed());
+        coordinate.putDouble("heading", location.getBearing());
         if(android.os.Build.VERSION.SDK_INT >= 18){
         coordinate.putBoolean("isFromMockProvider", location.isFromMockProvider());
         }

lib/ios/AirGoogleMaps/AIRGoogleMap.m

@@ -789,6 +789,7 @@ - (void)observeValueForKeyPath:(NSString *)keyPath
                     @"accuracy": @(location.horizontalAccuracy),
                     @"altitudeAccuracy": @(location.verticalAccuracy),
                     @"speed": @(location.speed),
+                    @"heading": @(location.course),
                     }
                 };