Some post-merge cleanup for automatic brightness adjustment

- Remove some unused strings
- Use (device-dependant) minimum brightness level (as calculated by
  DisplayPowerController) as '0%' instead of the actual value 0.

Change-Id: I79123d2421c9ab35fa0f1808d82d785463e8fbaa
Settings: Remove redundant lines

Change-Id: I8f049386a6860bb3990fb56013beb9c9022b8bd7
Merge branch 'cm-10.1' of git://github.com/CyanogenMod/android_packages_apps_Settings into cm-10.1-n7