Add both map style support. From json and from mapbox url

Author: babeone

android/rctmgl/src/main/java/com/mapbox/rctmgl/components/mapview/RCTMGLMapView.java

@@ -422,8 +422,11 @@ public void waitForLayer(String layerID, FoundLayerCallback callback) {
     public void onMapReady(final MapboxMap mapboxMap) {
         mMap = mapboxMap;
 
-        //mMap.setStyle(new Style.Builder().fromUrl(mStyleURL));
-        mMap.setStyle(new Style.Builder().fromJson(mStyleURL));
+        //if the myStyleURL contains "mapbox" the library will get the style from internet, else myStyleURL is a json and the library will load it
+        if(mStyleURL.substring(0,6).contains("mapbox"))
+            mMap.setStyle(new Style.Builder().fromUrl(mStyleURL));
+        else
+            mMap.setStyle(new Style.Builder().fromJson(mStyleURL));
 
         reflow();