LockScreen: Add option to start widgets maximized

Sources from AOKP with some modifications

This will allow the user to choose wether the lockscreen
challenge (circle, pattern, pin) is minimized when the screen
is turned on.

Patch Set 3: Remove visual jump and adhere to setting on initial inflate
Patch Set 4: Remove accidental dependency
Patch Set 5: Fix potential multi-user problem.

Signed-off-by: Dirk Rettschlag <dirk.rettschlag@gmail.com>
Change-Id: Ib5bd0a84e5542a49d34ed8c8541e10a7878a616c