- Add additional Listener methods to DownloadManager, to inform of
changes to whether the downloads are paused or waiting for requirements.
- Only schedule the Scheduler if we really are waiting for requirements.
- Only restart the service if we're no longer waiting for requirements,
and if there are queued downloads that will now be restarted.
Previously the service would be restarted whenever the requirements
were met, regardless of whether there was any work to do.
- Restart service if it might be stopping, as well as if it's already
stopped. Also restart service if there's a download state change to a
state for which the service should be started, if.
Issue: #6798
PiperOrigin-RevId: 290270547
a7f7d8fb03