Camera Tile : Close on flip/switch

Summary:
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

Test Plan: tested, merge

Reviewers: synergy

Reviewed By: synergy

Differential Revision: http://review.codefirex.com/D521