Fixes AssistOrbController crash

AssistOrbController caused a crash by trying to remove a view that was
not attached. This change adds a check if the view is attached before
removal.

Test: Tested locally
BUG: 195902117
FIX: 195902117
Change-Id: Ibc65a9b1789c7ee629c28de31392fffc0536ed70
1 file changed