We inadvertently shipped 4.17 with kube-apiserver serving admissionregistration.k8s.io/v1beta1. Users may have grown dependencies here, so we need to do a phased removal with admin ack requirement (begin flagging as deprecated in 4.17.z and stop serving for 4.20 GA).

Noticed in https://github.com/openshift/api/pull/2249 and introduced in https://github.com/openshift/api/pull/1888 with intent to fix before GA in https://github.com/openshift/cluster-kube-apiserver-operator/pull/1687.

Checklist:

1. Register GVRs with deprecated API filter and backport to 4.18.z. Backporting to 4.17.z has little value because the alerts for this condition fire only for "removed in next" and "removed in next EUS".
   1. 4.20.0: https://github.com/openshift/kubernetes/pull/2287
   2. 4.19.z: https://github.com/openshift/kubernetes/pull/2290
   3. 4.18.z: https://github.com/openshift/kubernetes/pull/2333
2. Disable serving this GV in cluster-kube-apiserver in 4.20.0+. (https://github.com/openshift/cluster-kube-apiserver-operator/pull/1836)
3. Require admin ack for 4.19-to-4.20 upgrades (https://github.com/openshift/cluster-version-operator/pull/1193).