Add basic High Brightness Mode implementation.

1) Loads configuration values from the display device config file
2) Passes those values through to AutomaticBrightnessController
3) Uses configuration in new HighBrightnessModeController class
   to drive High Brightness mode via AutomaticBrightnessController.

Test: manual.  Set HBM to enabled in display-config file.
Bug: 168210138
Change-Id: I4824bbc9d97cb668efc3bcaddb036d508a40fa87