Moving BatterySaverPolicy into batterysaver directory.

This should make adding new methods that shouldn't be public easier.

Bug: 119261320
Test: atest com.android.server.power.PowerManagerServiceTest
and com.android.server.power.batterysaver.BatterySaverPolicyTest
and com.android.server.power.batterysaver.BatterySaverStateMachineTest

Change-Id: I8fdba4257be3d5602a738d2fffd55385775c3f81
11 files changed