Fix a few issues with occluded Keyguard

- When we get a collapse before the layout happened in SystemUI,
don't expand the panel after the layout.
- Don't reset waitingToShow when coming out of sleep. This will cause
win.isVisibleOrBehindKeyguardLw to return false and then occluded
state will change rapidly from true -> false -> true, leading to
flickering in SysUI.

Bug: 23898941
Change-Id: I2b941188de777086bb2b477f5bfc00cc0cd6abe0