Pass FlatViewGroup to DrawCommand.draw()

Summary: @public To render `View`s inside `FlatViewGroup`, we need to pass the parent to `DrawCommand.draw()` method. Used in a followup diff.

Reviewed By: sriramramani

Differential Revision: D2564478

ReactAndroid/src/main/java/com/facebook/react/flat/DrawTextLayout.java

@@ -31,7 +31,7 @@ import android.text.Layout;
   }
 
   @Override
-  public void draw(Canvas canvas) {
+  public void draw(FlatViewGroup parent, Canvas canvas) {
     float left = getLeft();
     float top = getTop();