Fix issue 2512221: Car Dock Notification doesn't go away

Bug description:
1) Start Car Dock app.
2) Drop phone into Desk Dock
3) Press back to quit Desk Dock app.

Car Dock Notification doesn't go away if I select it from the shade.

Change-Id: I9d3ad4dbbe8f886fc8d523d104676194c3943473
1 file changed