Bring PVC Protection Feature to Beta

The PR: kubernetes/kubernetes#59052
brought PVC Protection feature to beta.

That's why the documentation is updated accordingly.

docs/admin/admission-controllers.md

@@ -414,8 +414,8 @@ This admission controller also protects the access to `metadata.ownerReferences[
 of an object, so that only users with "update" permission to the `finalizers`
 subresource of the referenced *owner* can change it.
 
-### Persistent Volume Claim Protection (alpha)
-{% assign for_k8s_version="v1.9" %}{% include feature-state-alpha.md %}
+### Persistent Volume Claim Protection (beta)
+{% assign for_k8s_version="v1.10" %}{% include feature-state-beta.md %}
 The `PVCProtection` plugin adds the `kubernetes.io/pvc-protection` finalizer to newly created Persistent Volume Claims (PVCs). In case a user deletes a PVC the PVC is not removed until the finalizer is removed from the PVC by PVC Protection Controller. Refer to the [PVC Protection](/docs/concepts/storage/persistent-volumes/#persistent-volume-claim-protection) for more detailed information.
 
 ### PersistentVolumeLabel

docs/concepts/storage/persistent-volumes.md

@@ -71,13 +71,13 @@ Pods use claims as volumes. The cluster inspects the claim to find the bound vol
 Once a user has a claim and that claim is bound, the bound PV belongs to the user for as long as they need it. Users schedule Pods and access their claimed PVs by including a `persistentVolumeClaim` in their Pod's volumes block. [See below for syntax details](#claims-as-volumes).
 
 ### Persistent Volume Claim Protection
-{% assign for_k8s_version="v1.9" %}{% include feature-state-alpha.md %}
+{% assign for_k8s_version="v1.10" %}{% include feature-state-beta.md %}
 The purpose of the PVC protection is to ensure that PVCs in active use by a pod are not removed from the system as this may result in data loss.
 
 **Note:** PVC is in active use by a pod when the the pod status is `Pending` and the pod is assigned to a node or the pod status is `Running`.
 {: .note}
 
-When the [PVC protection alpha feature](/docs/tasks/administer-cluster/pvc-protection/) is enabled, if a user deletes a PVC in active use by a pod, the PVC is not removed immediately. PVC removal is postponed until the PVC is no longer actively used by any pods.
+When the [PVC protection beta feature](/docs/tasks/administer-cluster/pvc-protection/) is enabled, if a user deletes a PVC in active use by a pod, the PVC is not removed immediately. PVC removal is postponed until the PVC is no longer actively used by any pods.
 
 You can see that a PVC is protected when the PVC's status is `Terminating` and the `Finalizers` list includes `kubernetes.io/pvc-protection`:
 ```shell

docs/tasks/administer-cluster/pvc-protection.md

@@ -6,18 +6,16 @@ title: Persistent Volume Claim Protection
 ---
 
 {% capture overview %}
-{% assign for_k8s_version="v1.9" %}{% include feature-state-alpha.md %}
+{% assign for_k8s_version="v1.10" %}{% include feature-state-beta.md %}
 
-As of Kubernetes 1.9, persistent volume claims (PVCs) that are in active use by a pod can be protected from pre-mature removal.
+As of Kubernetes 1.10, persistent volume claims (PVCs) that are in active use by a pod can be protected from pre-mature removal.
 
 {% endcapture %}
 
 {% capture prerequisites %}
 
-- A v1.9 or higher Kubernetes must be installed.
-- As PVC Protection is a Kubernetes v1.9 alpha feature it must be enabled:
-1. [Admission controller](/docs/admin/admission-controllers/) must be started with the [PVC Protection plugin](/docs/admin/admission-controllers/#persistent-volume-claim-protection-alpha).
-2. All Kubernetes components must be started with the `PVCProtection` alpha features enabled.
+- A v1.10 or higher Kubernetes must be installed.
+- The PVC Protection feature is enabled by default in Kubernetes v1.10 so it does not have to be enabled manually.
 
 {% endcapture %}