SystemUI: Fix potential NPE
Does already cause issues on some Halo ports to other ROMs.
Might not cause issues on PA (yet), but better safe than sorry.

Change-Id: I0ac29c0544cee7679d19624e5e9ced1e79b3ab1b
Camera Tile : Close on flip/switch

Currently the camera tile only checks whether the
container panel is fully expanded. This doesnt take into account
when the user swipes to another panel via handle bar swipe, or by
pressing the switch button in the top right of the drawer.

Reproduction steps :
    Go to quick settings panel
    Enable camera tile
    Switch to notifications via swipe or switch button
    Camera preview stays persistent behind drawer

This patchset also makes the view hierarchy lookups one time, rather than
on each runnable run which is quite frequent (100ms).

Change-Id: Ic803744b63613d1e58b3efd4a92d052a16e5a2bd
RebootTile: This should make it work
Revert "Camera Tile : Close on flip/switch"

This reverts commit cdcbdabd7e2419e0f141de729aedae05448cb820.