* Added Establishing Controller on CRDs to avoid race between Established condition and CRs actually served. In HA setups, the Established condition is delayed by 5 seconds. ([#63068](https://github.com/kubernetes/kubernetes/pull/63068), [@xmudrii](https://github.com/xmudrii))

## Changes by Kind

### Deprecation

#### kube-apiserver:
- the following deprecated APIs can no longer be served:
  - All resources under `apps/v1beta1` and `apps/v1beta2` - use `apps/v1` instead
  - `daemonsets`, `deployments`, `replicasets` resources under `extensions/v1beta1` - use `apps/v1` instead

- `Ingress` and `IngressClass` resources have graduated to `networking.k8s.io/v1`. Ingress and IngressClass types in the `extensions/v1beta1` and `networking.k8s.io/v1beta1` API versions are deprecated and will no longer be served in 1.22+. Persisted objects can be accessed via the `networking.k8s.io/v1` API. Notable changes in v1 Ingress objects (v1beta1 field names are unchanged):
  - `spec.backend` -> `spec.defaultBackend`