Always set correct policy visibility

Windows without a surface didn't get the correct policy visibility
applied after dismissing lockscreen. Thus, when launching something
from lockscreen, home activity was hidden but never set to visible
again. Before executing the transition to home, we didn't consider
home as a wallpaper target because it was still invisible, and thus
we picked the wrong transition.

Always applying policy visibility when lockscreen changes fixes this
outdated state.

Bug: 18369599
Change-Id: I2933eaf0ab55fe31cb382c46c411033e33a756e0