Pass touch events on to the ScaleGestureDetector

Note that the listener doesn't do anything with the scale gestures yet,
though. I guesss either a new type of VCL event is needed for zooming, or then
we could fake entering of Control-+ and Control-- key events (or whatever the
default bindings for zoom in and out are).

Change-Id: Ib2ba138dd3e7874f85e9fc9fb7ac7198fa6212d3

android/experimental/desktop/src/org/libreoffice/experimental/desktop/Desktop.java

@@ -226,6 +226,8 @@ public class Desktop
 
         @Override public boolean onTouchEvent(MotionEvent event)
         {
+            gestureDetector.onTouchEvent(event);
+
             if (!renderedOnce)
                 return super.onTouchEvent(event);