OutdoorModeController: Unconditionally enable auto mode on HWC2

 * On HWC2, setting "Display mode" to "Automatic" and disabling
   "Automatic outdoor mode" at the same time makes no difference with
   setting "Display mode" to "Off" alone. Obviously this is redundant
   and could confuse the user, so simply ignore the "Automatic outdoor
   mode" setting on HWC2 to reduce redundancy.

Change-Id: I6858571a6b9ded3540fd3d936499878f57a7b3d4