Move noteAppWidgetTapped call into AppWidgetHostView.

RemoteViews is public API used out of scope of widget. The correct place
to call noteAppWidgetTapped is in AppWidgetHostView.

Fix: 153676411
Test: manual test, tap a widget, "adb shell dumpsys usagestats | grep
USER_INTERACTION" to oberserve USER_INTERACTION event sent to UsageStas, "adb shell dumpsys appops | grep appWidgetVisible" to observer appWidgetVisible flag.

Change-Id: Ic473211b91fd952dbb81b09b1e1568d6f69a0dd8