Add runtime styling APIs on MapSnapshotter (#268)

* Add styleable snapshotter.

* Add style API for snapshotter

* Add observer interface to snapshotter

* WIP Add styling to snapshotter activity

* Update interface and implement addlayer functions.

* Deprecate methods instead of removing

* Implement addSource functions.

* Implement addImage function

* Still use the previous callback interface.

* Expose onStyleDidloaded interface

* Add setStyle method

* Start native snapshotter from start method

* Fix snapshotter test.

* Fix check style

* Keep the original interface

* Update gl-native

* Add demo for snapshotter heatmap layer

* bump gl-native

Co-authored-by: Alexander Shalamov <alexander.shalamov@mapbox.com>

MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/MapboxMap.java

@@ -5,12 +5,6 @@ import android.graphics.Bitmap;
 import android.graphics.PointF;
 import android.graphics.RectF;
 import android.os.Bundle;
-import androidx.annotation.FloatRange;
-import androidx.annotation.IntRange;
-import androidx.annotation.NonNull;
-import androidx.annotation.Nullable;
-import androidx.annotation.Size;
-import androidx.annotation.UiThread;
 import android.text.TextUtils;
 import android.view.View;
 
@@ -44,6 +38,13 @@ import com.mapbox.mapboxsdk.style.expressions.Expression;
 import java.util.ArrayList;
 import java.util.List;
 
+import androidx.annotation.FloatRange;
+import androidx.annotation.IntRange;
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.annotation.Size;
+import androidx.annotation.UiThread;
+
 /**
  * The general class to interact with in the Android Mapbox SDK. It exposes the entry point for all
  * methods related to the MapView. You cannot instantiate {@link MapboxMap} object directly, rather,
@@ -93,6 +94,13 @@ public final class MapboxMap {
     this.developerAnimationStartedListeners = developerAnimationStartedListeners;
   }
 
+  /**
+   * Trigger the mapview to repaint.
+   */
+  public void triggerRepaint() {
+    nativeMapView.triggerRepaint();
+  }
+
   void initialise(@NonNull Context context, @NonNull MapboxMapOptions options) {
     transform.initialise(this, options);
     uiSettings.initialise(context, options);