Camera button support [1/2]

Original commit - https://github.com/CyanogenMod/android_frameworks_base/commit/e0749499766be45165b912d0c6400f4c69982fe4

Credit/Thanks to @NeverGone-RU

Change-Id: I2de3036d98807d35ea99c2bddbafc2f5dc2cd9aa
Merge "Camera button support [1/2]" into du44