- Remove NETWORK_TYPE_NOT_ROAMING and NETWORK_TYPE_METERED
because JobScheduler doesn't support them, and they're
probably not useful to many people (data when roaming is
normally enabled/disabled at the OS level, and restricting
to *only* metered networks seems niche)
- Convert network requirements proper flags
- Stop persisting requirements in DownloadIndex. The direction
we're headed to solve the manager start/stop problem is
going to involve state in DownloadManager determining whether
downloads actually start, and if we're doing that then it's
no worse to do it for this as well
PiperOrigin-RevId: 242713196
3f565c33be