units: enable systemd-networkd-wait-online.service, disable all journal-remote stuff

The preset for systemd-networkd-wait-online.service should match
whatever we do for systemd-networkd.service. s-n-wait-online.service
is only pulled in when some other unit pulls in network-online.target,
otherwise it's not used. But if something pulls in network-online.target,
they should expect s-n-wait-online.service to be active iff
systemd-networkd.service is active.

OTOH, the journal-remote and journal-upload services should be disabled
by default, since they don't do anything without additional configuration.