Hook up Adaptive Battery to new flag.

APP_STANDBY_ENABLED is controlled by server side to do experiment.
Before this CL, Adaptive Battery is hooked up to this flag, so
even though if user turns it off, it may be turned on by server.

Add a high level ADAPTIVE_BATTERY_MANAGEMENT_ENABLED to control
the feature in settings UI side.

Bug: 78153913
Test: RunSettingsRoboTests
Change-Id: I1a18d622ddc31ec4d45db918bf981516fbb926c1