Revert "Promote DeviceStateManager to System API and update Devi..."

Revert submission 26228978-device-state-callbacks

Reason for revert: <Potential culprit for b/325379002  - verifying through ABTD before revert submission. This is part of the standard investigation process, and does not mean your CL will be reverted.>

Reverted changes: /q/submissionid:26228978-device-state-callbacks

Change-Id: I36c55815cc0b8cb9caf4dc75db1bd4dcc2188757