Manila Ganesha is not always deployed in an ha configuration in
functional tests. This means there is no automated restart of the
manila services but the _restart_share_instance method shuts down
manila services via systemctl and expects them to be automatically
started. This change detects if the hacluster charm is present, if
it is it defaults it used the old behaviour otherwise systemctl
is used to restart the services.
778d36e1fa