Revert "Revert "Gamma Corrected Brightness: Recalculate backlight intensity based on gamma presets""

This reverts commit c2c9728639a5242d18badf7df74ec200f3ad37a1.

Change-Id: I95f37db9623052635fe34579d3aa3e6c2eaba882
Merge "Revert "Revert "Gamma Corrected Brightness: Recalculate backlight intensity based on gamma presets""" into du44