Respect per-user rotation lock et alia

Various per-user settings such as rotation lock are relevant to the
singleton PhoneWindowManager object.  We now listen for user-switch
broadcasts and reconfigure the active state based on the newly-
active user's settings.

The RotationPolicy toolset has also been updated to do the right
thing, as has the Quick Settings UI.

Bug 7213638

Change-Id: Iee2109e48df550b4c979d3f9c91b5d2b71a6a08e