https://issues.redhat.com/browse/OCPBUGS-23957 introduced a change in behavior the we should document.

For clusters that have the `.spec.defaultNetwork.ovnKubernetesConfig.gatewayConfig.ipForwarding`field set to `Restricted` in the network.operator object we set the default policy of the FORWARD iptables chain to DROP.

It is further described here: https://github.com/kyrtapz/ovn-kubernetes/blob/681f7cabc2aa5782bfea93506044f292df631cb7/docs/getting-started/configuration.md#forwarding-rules