Settings:  allow device trees to invoke custom display settings

in this case gesture control settings.

Intent used: com.slim.action.LAUNCH_SCREEN_OFF_GESTURE_SETTINGS

Due that the methods to inject external settings have changed on lp due of
the dashboard we reintroduce a simply meta data preference method which can setup
on wherever sub settings screen an entry with title and summary.

Change-Id: I82f5a8a4075f109419b08014ad2d723bf2f54402
Settings: add a default slim actions array

Change-Id: Icb6725834c83f4e64964f8d5b7d6a06c16260a49
Settings: add default slim actions for screen off gestures

Change-Id: Ia7c59308d7ea0b8764e3a9e181625d08834a3881
Settings: Materialize DSLV

Change-Id: I8efe75ee2b571136a7983b9a0b36090294650c80
Merge remote-tracking branch 'slim/lp5.0-caf' into lp5.0-caf