Update ovnKubernetesConfig.policyAuditConfig Default

We need to initialize `ovnKubernetesConfig.policyAuditConfig`
so that the proper defaults are populated when a CNO config
object is created

It would be better to do this using the `+kubebuilder:default`
flag however it is broken for this case as described in this
[upstream issue](kubernetes-sigs/controller-tools#622)

Signed-off-by: astoycos <astoycos@redhat.com>

TMP