Salt: Add more dependencies to systemd services

This may help Salt reload services correctly, although we still
need the script until Salt's bug with reloading services on systemd
is resolved.

Salt bug: https://github.com/saltstack/salt/issues/16778

cluster/saltbase/salt/docker/init.sls

@@ -151,6 +151,9 @@ docker:
     - enable: True
     - watch:
       - file: {{ environment_file }}
+{% if pillar.get('is_systemd') %}
+      - file: {{ pillar.get('systemd_system_path') }}/docker.service
+{% endif %}
 {% if override_docker_ver != '' %}
     - require:
       - pkg: lxc-docker-{{ override_docker_ver }}