Move the display targeted by a key event to top

In a single-focus multi-display system, if a key event targeting a
non-focused display, we move the display to top. And then send the
key event to the display when it become top-focused.

This change also updates the window manager lock.

Change-Id: I15e99fe09fe0912cdfa0295f7ae5835d2dd6072d
Fix: 121057974
Test: atest WindowFocusTests