Add back backlight curve adjustment.

PS2:Fixed ok string, moved AutoBrightnessCustomizeDialog.java out of CM folder
PS3:Fixed minor derp

Change-Id: I4f55091c5d8c72301c0985fa8463d198f86a7d21
Signed-off-by: kecinzer <kecinzer@gmail.com>
Settings: fix incorrect value in autobrightness adjustment

If the user drag the progress bar below the min value, the incorrect
setting will be saved since seekBar.setProgress code path does not
return to the "getItem(pos).backlight = ..." line.

Change-Id: I4796e22ba9c44315be92de4040f6cd8451bdf153