Fix #2269582 Sometimes camera preview screen is truncated

There were a few places in the window manager where we wouldn't cause
a layout after making a window visible.  This would leave it using
whatever size and position it last have since we don't layout windows
when they are not visible.

Also includes a little part I missed in the security issue that
allowed wallpapers to see input on the lock screen.

Change-Id: Icd7e037ad9a67ac936bc7039d87ed68f49502d73