drawerhost DrawerClosing event only work when close one drawer by use command

[eijjxx]

when click other place to close drawer or use close all drawer command the DrawerClosing event doesn't work

[Keboo]

Reproduction steps in the demo app

1. Add a DrawerClosing event handler to the DrawerHost inside of Drawers.xaml. The event handler can be an empty method.
2. Add a break point to the event handler
3. Run the demo app and open the Drawers page. Open one of the drawers and click on the "CLOSE THIS" button. Observed: The break point in the event handler is hit.
4. Open on the drawers and click on the overlay in the middle of the drawer host to dismiss the drawer. Observed: The break point is not hit.

Expected: The event should be raised anytime the drawer is closed.

[nicolaihenriksen]

@Keboo Following you repro steps above, I cannot reproduce this. Breakpoint is hit in both cases.