Use new getBrighntessInfo() API for brightness

The slider and settings need to use the new brightness
api so that:
1) It can work for mutiple-displays that support brightness
2) Can work with high-brightness mode which can dynamically
adjust the brightness min and max.

Bug: 168210311
Test: Verify that slider can go to 100% with HBM on or off.
Test: atest com.android.settings.display
Change-Id: I01029e211f64f0a8598b1388dd3bb535eb0beb69