Move BatteryInfo to settings from settingslib

This CL simply moves BatteryInfo from settingslib to settings and
makes sure the tests still pass. No other changes are made other than
imports or minor changes needed to make sure existing code does not
break.

Test: Robotests still pass
Bug: 38399275
Bug: 38398949
Bug: 38399654
Change-Id: I59803348e2780b7676ccc6c43234a586c184d71f