Add listener for brightness-specific changes.

Add FLAG to registerDisplayListener method to receive
brightness-specific changes.

getBrightnessInfo() method added to
android.view.Display to get brightness value, min, max
and highBrightnessMode status.

Bug: 168210311
Bug: 171023136
Test: atest com.android.server.display
Change-Id: I581e86e039cc7cf1bbca4cf7af03daa41dbddfe0
14 files changed