Ch16 OPA gatekeeper specification invalid

[Alibirb]

The opa/gatekeeper.yaml file requires modifications to work with Kubernetes 1.22 due to API changes (mainly removal of v1beta1 API). I had to make the following changes to get kubectl to apply it:

• Change all occurrences of apiextensions.k8s.io/v1beta1 in apiVersion to apiextensions.k8s.io/v1 (don't touch the v1beta1s within spec.versions, because those refer to versions of custom resources which Gatekeeper will attempt to use itself)
• Add admissionReviewVersions: ["v1"] to both entries for webhook in the ValidatingWebhookConfiguration
• Remove all spec.version fields in CustomResourceDefinition
• All spec.validation fields in CustomResourcDefiniton must be renamed to schema and moved into each entry in spec.versions
• For the constrainttemplates.templates.gatekeeper.sh CustomResourceDefinition, add type: object to schema.openAPIV3Schema for each entry in spec.versions

This gets kubectl to apply the definitions and the controller runs, but applying the requiredLabels.yaml constraint fails claiming parameters is an unknown field, so it seems there are some additional changes to be made somewhere.