Hook up notification history to NMS.

All of the lifecycle events for the history are in place now with
the exception of triggering a write when the power button is
long pressed

The new tests interacted with DeviceConfig in such a way that
callbacks were being received after tests were completed, so I
also had to add an unregistration step for the DeviceConfig
listener.

Test: atest
Bug: 137396965
Change-Id: I9ad1197105a5c2434444965a1649485e36e4b692