The dashboard nodes (alertmanager, grafana, node-exporter, and prometheus)
were not manage during the docker to podman migration.
This adds the systemd container template of those services to a dedicated
file (systemd.yml) in order to include it in the docker2podman playbook.
This also adds the dashboard container images pull from docker to podman.
Closes: https://bugzilla.redhat.com/show_bug.cgi?id=1829389
Signed-off-by: Dimitri Savineau <dsavinea@redhat.com>