Use appropriate notify method instead

Use notifyAppWidgetViewDataChanged(int[] appWidgetIds, int viewId)
instead of invoking notifyAppWidgetViewDataChanged(int appWidgetId,
int viewId) in the loop

Change-Id: Ic227640e720cc35a652c0a89d39f633bab338cc7
Signed-off-by: Roger Chen <cxr514033970@gmail.com>