If we've disabled scrolling within the map, then don't capture the touch events (#664)

* If we've disabled scrolling within the map, then don't capture the touch events. This allows the containing scrollview to perform a scrollview scroll by dragging on the map. (Previously, the map would absorb the touches, and then not scroll the map *or* the scrollview, which was bad.)

* Minor simplification

Author: mikelambert

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

@@ -571,13 +571,15 @@ public boolean dispatchTouchEvent(MotionEvent ev) {
 
         switch (action) {
             case (MotionEvent.ACTION_DOWN):
-                this.getParent().requestDisallowInterceptTouchEvent(true);
+                this.getParent().requestDisallowInterceptTouchEvent(
+                        map != null && map.getUiSettings().isScrollGesturesEnabled());
                 isTouchDown = true;
                 break;
             case (MotionEvent.ACTION_MOVE):
                 startMonitoringRegion();
                 break;
             case (MotionEvent.ACTION_UP):
+                // Clear this regardless, since isScrollGesturesEnabled() may have been updated
                 this.getParent().requestDisallowInterceptTouchEvent(false);
                 isTouchDown = false;
                 break;