Add back backlight brightness curve adjustment
Fix race condition in backlight adjustment.

When configuring the automatic backlight levels, there's a race
condition in setting the lux and brightness settings as the settings
provider doesn't allow storing multiple settings atomically. When
deleting rows, there's quite a high chance of DisplayPowerController
picking up a state where the lux values already have the lower number of
rows, but the brightness values do not, effectively leading to an
ArrayIndexOutOfBoundsException.

Fix that by
- waiting a second of cool-down time until applying the settings and
- adding a sanity check for the very unlikely case that the delay
  between writing both values is > 1 second

Change-Id: I44e41530fc5334aaefc4ab7d3a90542f78fabe0c
JIRA:CYAN-755
Improve auto-brightness handling
Re-add auto brightness configuration UI(1/2)
fixed some derps for AOSP
Add method to PowerManager that allows querying the lowest possible
brightness.

Used by the auto-brightness adjustment to adjust the sliders.

Change-Id: Idb58fd86dee1a053fe858291be6c9b3169ac4247
Changed color of lockscreen reboot and screenshot picture to fit the current design
Allow adjusting progress on touch events.

Change-Id: Ide0a7ae057a62f3631a32eeaa63f3e04dec5bf54