Android: fix scrolling using a touch keyboard on Blackberry

This is a follow-up commit to 97eec16e.

Blackberry tries sending touchpad events first, and if not consumed,
it sends synthetic mouse wheel events as a fallback. This makes touch
keyboard scrolling work in native Android ListViews and other views
that do not handle SOURCE_TOUCHPAD motion events. Qt apps, however,
blindly accepted all generic motion events, so synthesized mouse wheel
events were never sent. => Make QtSurface & QtNative accept only those
motions events that are actually handled.

Task-number: QTBUG-51165
Change-Id: Iefbbf1e3e1cc3da86afc4c87c19671cc6c5fa145
Reviewed-by: Kai Uwe Broulik <kde@privat.broulik.de>
Reviewed-by: BogDan Vatra <bogdan@kdab.com>

src/android/jar/src/org/qtproject/qt5/android/QtNative.java

@@ -471,15 +471,16 @@ public class QtNative
         }
     }
 
-    static public void sendGenericMotionEvent(MotionEvent event, int id)
+    static public boolean sendGenericMotionEvent(MotionEvent event, int id)
     {
         if (event.getActionMasked() != MotionEvent.ACTION_SCROLL
                 || (event.getSource() & InputDevice.SOURCE_CLASS_POINTER) != InputDevice.SOURCE_CLASS_POINTER) {
-            return;
+            return false;
         }
 
         mouseWheel(id, (int) event.getX(), (int) event.getY(),
                        event.getAxisValue(MotionEvent.AXIS_HSCROLL), event.getAxisValue(MotionEvent.AXIS_VSCROLL));
+        return true;
     }
 
     public static Context getContext() {

src/android/jar/src/org/qtproject/qt5/android/QtSurface.java

@@ -116,7 +116,6 @@ public class QtSurface extends SurfaceView implements SurfaceHolder.Callback
     @Override
     public boolean onGenericMotionEvent(MotionEvent event)
     {
-        QtNative.sendGenericMotionEvent(event, getId());
-        return true;
+        return QtNative.sendGenericMotionEvent(event, getId());
     }
 }