add documentation for KEP 4017 PodIndexLabel going GA

Signed-off-by: Alay Patel <alayp@nvidia.com>

content/en/docs/concepts/workloads/controllers/statefulset.md

@@ -252,13 +252,13 @@ the StatefulSet.
 
 ### Pod index label
 
-{{< feature-state for_k8s_version="v1.28" state="beta" >}}
+{{< feature-state feature_gate_name="PodIndexLabel" >}}
 
 When the StatefulSet {{<glossary_tooltip text="controller" term_id="controller">}} creates a Pod,
 the new Pod is labelled with `apps.kubernetes.io/pod-index`. The value of this label is the ordinal index of
 the Pod. This label allows you to route traffic to a particular pod index, filter logs/metrics
-using the pod index label, and more. Note the feature gate `PodIndexLabel` must be enabled for this
-feature, and it is enabled by default.
+using the pod index label, and more. Note the feature gate `PodIndexLabel` is enabled and locked by default for this
+feature, in order to disable it, users will have to use server emulated version v1.31.
 
 ## Deployment and Scaling Guarantees
 

content/en/docs/reference/command-line-tools-reference/feature-gates/pod-index-label.md

@@ -9,5 +9,9 @@ stages:
   - stage: beta
     defaultValue: true
     fromVersion: "1.28"
+    toVersion: "1.31"
+  - stage: stable
+    defaultValue: true
+    fromVersion: "1.32"
 ---
 Enables the Job controller and StatefulSet controller to add the pod index as a label when creating new pods. See [Job completion mode docs](/docs/concepts/workloads/controllers/job#completion-mode) and [StatefulSet pod index label docs](/docs/concepts/workloads/controllers/statefulset/#pod-index-label) for more details.