Settings: AdaptiveBacklight support

Add support for adaptive backlight technologies like NVIDIA SmartDimmer, QCOM CABL or Samsung CABC.

Patchset 2: Use internal shared prefs to store the smardimmer setting
Patchset 3: Rename to AdaptiveBacklight
Patchset 4: Reorganize settings and strings to follow design guidelines
Patchset 5: CleanUp
Patchset 6: Added suggestions
Patchset 7: Sync default value. CleanUp.

Depends	on http://review.cyanogenmod.org/#/c/48465/
Contains: https://github.com/CyanogenMod/android_packages_apps_Settings/commit/310a19ac41001e1649129e7c29f50de08720f29a

Change-Id: Ib0e05770bf90b664a00e65f46d32cc9a07be1377