settings: Add support for SRE

 * Add support for sunlight readability enhancement
 * Optionally depends on adaptive backlight, depending on HAL

Change-Id: I9ca388ffd68080f0e497edb81d5f8616c194ea1d
Merge branch 'cm-11.0' of https://github.com/CyanogenMod/android_packages_apps_Settings into android-4.4