openstack-helm/openstack/values_overrides/neutron/netpol.yaml

---
neutron:
  manifests:
    network_policy: true
  network_policy:
    neutron:
      egress:
        - to:
          - ipBlock:
              cidr: %%%REPLACE_API_ADDR%%%/32
          ports:
            - protocol: TCP
              port: %%%REPLACE_API_PORT%%%
...