QuietHours cleanup.  Remove duplicate code

See original code here: https://github.com/SaberMod/android_frameworks_base/blob/b6b3fa3dbc0825d4276e31cf3f2c31cb1422af0a/services/java/com/android/server/BatteryService.java#L693
Signed-off-by: Paul Beeler <sparksco@gmail.com>