cc_ssh: sshd is not enabled on *BSD

[Mina Galić]

Most BSD systems don't come with many services enabled, so taking a standard FreeBSD VM image and putting cloud-init on it will generate SSH keys, but it won't enable sshd

I reckon we can use distros.rhel_util to set `sshd_enable=YES`

We can then start the service or rely on a reboot.

[Mina Galić (minagalic)]

the following logic in `handle_ssh_pwauth()`:

        if not uses_systemd:
            LOG.debug(
                "Writing config 'ssh_pwauth: %s'. SSH service '%s'"
                " will not be restarted because it is not running or not"
                " available.",
                pw_auth,
                service,
            )
            restart_ssh = False

could be enhanced to enable the service if the status fails
But perhaps this would need a flag somewhere.

[James Falcon (falcojr)]

Tracked in Github Issues as https://github.com/canonical/cloud-init/issues/4015