This container can be pulled via:
  docker pull registry.opensuse.org/devel/bci/sle-15-sp7/containerfile/suse/kiosk/firefox-esr:153.3
  docker pull registry.opensuse.org/devel/bci/sle-15-sp7/containerfile/suse/kiosk/firefox-esr:153.3-290.43
  docker pull registry.opensuse.org/devel/bci/sle-15-sp7/containerfile/suse/kiosk/firefox-esr:esr
  docker pull registry.opensuse.org/devel/bci/sle-15-sp7/containerfile/suse/kiosk/firefox-esr:latest

Set DOCKER_CONTENT_TRUST=1 to enable image tag verification.