Automatic merge from submit-queue (batch tested with PRs 39625, 39842)

Add RBAC v1beta1

Add `rbac.authorization.k8s.io/v1beta1`.  This scrubs `v1alpha1` to remove cruft, then add `v1beta1`.  We'll update other bits of infrastructure to code to `v1beta1` as a separate step.

```release-note
The `attributeRestrictions` field has been removed from the PolicyRule type in the rbac.authorization.k8s.io/v1alpha1 API. The field was not used by the RBAC authorizer.
```

@kubernetes/sig-auth-misc @liggitt @erictune