Allow quick scrub/switch from minus one

Launcher's window doesn't have focus when on minus one. In this case, we
tell the minus one overlay to hide and add a window focused callback to
start quick scrub/switch after launcher regains focus. Since the
transition from minus one takes longer than for launcher to get window
focus, we also defer until the overlay is completely hidden before
starting the quick scrub transition.

Bug: 70180755
Change-Id: Ifcf85aaf1942b51394e68e209b89807fa4007afe