// Defaulted to nil.
  // +optional
  optional bool immutable = 5;

  // Data contains the secret data. Each key must consist of alphanumeric
  // characters, '-', '_' or '.'. The serialized form of the secret data is a
  // base64 encoded string, representing the arbitrary (possibly non-string)
  // data value here. Described in https://tools.ietf.org/html/rfc4648#section-4
  // +optional

- Restartable init containers resource in pod autoscaler are now calculated. ([#120001](https://github.com/kubernetes/kubernetes/pull/120001), [@qingwave](https://github.com/qingwave))
- Sidecar termination is now serialized and each sidecar container will receive a `SIGTERM` after all main containers and later starting sidecar containers have terminated. ([#120620](https://github.com/kubernetes/kubernetes/pull/120620), [@tzneal](https://github.com/tzneal))