iptables failing to start during Overcloud update

Issue

• During overcloud update while running:

openstack overcloud upgrade run --nodes Controller --skip-tags validation

The update fails with the following error:

          "Error: Systemd start for iptables failed!",
          "journalctl log for iptables:",
          "-- Logs begin at Fri 2019-09-27 15:15:00 UTC, end at Sun 2019-09-29 17:15:54 UTC. --",
          "Mar 07 12:24:54 overcloud-controller-0 systemd[1]: Starting IPv4 firewall with iptables...",
          "Mar 07 12:24:54 overcloud-controller-0 iptables.init[68001]: iptables: Applying firewall rules: iptables-restore v1.4.21: Set NIPv4d5a73434-6ab7-436e-e17f- doesn't exist.",
          "Mar 07 12:24:54 overcloud-controller-0 iptables.init[68001]: Error occurred at line: 230",
          "Mar 07 12:24:54 overcloud-controller-0 iptables.init[68001]: Try `iptables-restore -h' or 'iptables-restore --help' for more information.",
          "Mar 07 12:24:54 overcloud-controller-0 iptables.init[68001]: [FAILED]",
          "Mar 07 12:24:54 overcloud-controller-0 systemd[1]: iptables.service: main process exited, code=exited, status=1/FAILURE",
          "Mar 07 12:24:54 overcloud-controller-0 systemd[1]: Failed to start IPv4 firewall with iptables.",
          "Mar 07 12:24:54 overcloud-controller-0 systemd[1]: Unit iptables.service entered failed state.",
          "Mar 07 12:24:54 overcloud-controller-0 systemd[1]: iptables.service failed.",