Add an automatic storage management job service.

This service runs once a day when plugged in when the device has
under 15% free space remaining. If the FeatureFactory has a
storage management job, it runs the job to begin to free up space
on the device.

This is a temporary landing place and will be refactored very
quickly out of Settings.

Bug: 28600825

Change-Id: Id2ebb42a333b3b4e3daef4e50cf985fe055b85c7