KEP 4818: PodLifecycleSleepActionAllowZero beta graduation (#49858)

* Docs PR for KEP 4818: Pod Lifecycle Sleep action allow zero value

* Update container-lifecycle-hooks.md

---------

Co-authored-by: Qiming Teng <[email protected]>

Author: sreeram-venkitesh

content/en/docs/concepts/containers/container-lifecycle-hooks.md

@@ -56,17 +56,20 @@ There are three types of hook handlers that can be implemented for Containers:
 Resources consumed by the command are counted against the Container.
 * HTTP - Executes an HTTP request against a specific endpoint on the Container.
 * Sleep - Pauses the container for a specified duration. 
-  This is a beta-level feature default enabled by the `PodLifecycleSleepAction` [feature gate](/docs/reference/command-line-tools-reference/feature-gates/). 
+  This is a beta-level feature default enabled by the `PodLifecycleSleepAction`
+  [feature gate](/docs/reference/command-line-tools-reference/feature-gates/). 
 
 {{< note >}}
-Enable the `PodLifecycleSleepActionAllowZero` feature gate if you want to set a sleep duration of zero seconds (effectively a no-op) for your Sleep lifecycle hooks.
+The beta level `PodLifecycleSleepActionAllowZero` feature gate which is enabled by default from v1.33.
+It allows you to set a sleep duration of zero seconds (effectively a no-op) for your Sleep lifecycle hooks.
 {{< /note >}}
 
 ### Hook handler execution
 
 When a Container lifecycle management hook is called,
 the Kubernetes management system executes the handler according to the hook action,
-`httpGet`, `tcpSocket` ([deprecated](/docs/reference/generated/kubernetes-api/v1.31/#lifecyclehandler-v1-core)) and `sleep` are executed by the kubelet process, and `exec` is executed in the container.
+`httpGet`, `tcpSocket` ([deprecated](/docs/reference/generated/kubernetes-api/v1.31/#lifecyclehandler-v1-core))
+and `sleep` are executed by the kubelet process, and `exec` is executed in the container.
 
 The `PostStart` hook handler call is initiated when a container is created,
 meaning the container ENTRYPOINT and the `PostStart` hook are triggered simultaneously. 
@@ -110,7 +113,9 @@ The logs for a Hook handler are not exposed in Pod events.
 If a handler fails for some reason, it broadcasts an event.
 For `PostStart`, this is the `FailedPostStartHook` event,
 and for `PreStop`, this is the `FailedPreStopHook` event.
-To generate a failed `FailedPostStartHook` event yourself, modify the [lifecycle-events.yaml](https://raw.githubusercontent.com/kubernetes/website/main/content/en/examples/pods/lifecycle-events.yaml) file to change the postStart command to "badcommand" and apply it.
+To generate a failed `FailedPostStartHook` event yourself, modify the
+[lifecycle-events.yaml](https://k8s.io/examples/pods/lifecycle-events.yaml)
+file to change the postStart command to "badcommand" and apply it.
 Here is some example output of the resulting events you see from running `kubectl describe pod lifecycle-demo`:
 
 ```

content/en/docs/reference/command-line-tools-reference/feature-gates/PodLifecycleSleepActionAllowZero.md

@@ -9,5 +9,9 @@ stages:
   - stage: alpha 
     defaultValue: false
     fromVersion: "1.32"
+    toVersion: "1.32"
+  - stage: beta
+    defaultValue: true
+    fromVersion: "1.33"
 ---
 Enables setting zero value for the `sleep` action in [container lifecycle hooks](/docs/concepts/containers/container-lifecycle-hooks/).