s4-common: use CAMCORDER_TX use case

Change-Id: I51392a00687db9f656ff7063ca03c7801682db57
s4-common: add support for capacitive button backlight brightness adjustment

Adds slider to "Backlight" option under "Buttons" settings menu
to adjust backlight brightness.

Requires http://review.cyanogenmod.org/49614

Thanks to LorD ClockaN for the original commit on m7-common
(http://review.cyanogenmod.org/49613) on which this commit was based.

Patch Set 3: Remove overlay change from common (will move to device folder)

Change-Id: I4e3bc29cecac54ea156ded613d2027c79a5e9b7e
Merge "s4-common: add support for capacitive button backlight brightness adjustment" into cm-10.2
s4-common: fix copy paste

Change-Id: I9b4951c3a162af50d5b9209984c620ed2a343eb1
Merge pull request #3 from CyanogenMod/cm-10.2

merge latest cm