Immediately close the shade when the status bar is disabled.

This provides a quick fix for http://b/2298803 (if the
in-call UI comes up while the user is holding the
windowshade, the shade sticks in place and the display
becomes unresponsive).

(NB: The shade disappears immediately when the status bar is
disabled. It might be better for the shade to animate
closed; indeed, this seems to be what the code was trying to
do, but an unfortunate interaction of the animation and
touch-handling code is what caused this bug in the first
place.)

Change-Id: I92a824fe385c8d6e51993be1657b492e580f1e7b