settings: Cleanup and add auto power profiles option

 * Add categories for all items
 * Add helper class for Settings.Secure

Change-Id: I9d8fd6720516e7fa321c05744ada81415cbf8aaa
Settings: remove lockscreen wallpaper picker from Lockscreen Interface

It should be accessed through the Themes interface.

Change-Id: Ibd893c82d4f1caf1c696474a17b5fceecc4ea1ab
Signed-off-by: Roman Birg <roman@cyngn.com>