- RemoteCommand feature gates for kubectl exec, cp, and attach over WebSockets are now enabled by default (Beta):
  - Server-side feature gate: `TranslateStreamCloseWebsocketRequests`
  - Client-side (kubectl) feature gate: `KUBECTL_REMOTE_COMMAND_WEBSOCKETS`

- Removed the `CronJobTimeZone` feature gate (the feature is stable and always enabled)
  - Removed the `JobMutableNodeSchedulingDirectives` feature gate (the feature is stable and always enabled)

- The `VolumeSnapshotDataSource` feature gate that is GA since v1.20 is unconditionally enabled, and can no longer be specified via the `--feature-gates` argument. ([#101531](https://github.com/kubernetes/kubernetes/pull/101531), [@ialidzhikov](https://github.com/ialidzhikov)) [SIG Storage]

  
  Portworx CSI driver is required to enable migration.
  This PR adds support of the `CSIMigrationPortworx` feature gate, which can be enabled by:
  
  1. Adding the feature flag to the kube-controller-manager `--feature-gates=CSIMigrationPortworx=true` 
  2. Adding the feature flag to the kubelet config:
  
  featureGates:

- The `AdvancedAuditing` feature gate that graduated to GA in `v1.12` (and was unconditionally
  enabled) has been removed. ([#118763](https://github.com/kubernetes/kubernetes/pull/118763), [@Shubham82](https://github.com/Shubham82))

### CSI Service Account Token

CSI Service Account Token feature moves to Beta in 1.21. This feature improves the security posture and allows CSI drivers to receive pods' [bound service account tokens](https://github.com/kubernetes/enhancements/blob/master/keps/sig-auth/1205-bound-service-account-tokens/README.md). This feature also provides a knob to re-publish volumes so that short-lived volumes can be refreshed.

- The `CSIMigrationAzureFile` feature gate (for the feature which graduated to GA in v1.26) is now unconditionally enabled and will be removed in v1.28. ([#114953](https://github.com/kubernetes/kubernetes/pull/114953), [@enj](https://github.com/enj))

- Lock ServerSideApply feature gate to true with the feature already being GA. ([#112748](https://github.com/kubernetes/kubernetes/pull/112748), [@wojtek-t](https://github.com/wojtek-t)) [SIG API Machinery, Apps, Instrumentation and Testing]

- Add a StorageVersionAPI feature gate that makes API server update storageversions before serving certain write requests. 
  This feature allows the storage migrator to manage storage migration for built-in resources. 

- Kubeadm: graduated the `UnversionedKubeletConfigMap` feature gate to Beta and enabled the feature by default. This implies that 1) for new clusters kubeadm will start using the `kube-system/kubelet-config` naming scheme for the kubelet ConfigMap and RBAC rules, instead of the legacy `kubelet-config-x.yy` naming. 2) during upgrade, kubeadm will only write the new scheme ConfigMap and RBAC objects. To disable the feature you can pass `UnversionedKubeletConfigMap: false` in the kubeadm config...