Revert v1.17 release changes on v1.16 branch (#18123)

This reverts commits:
  1131f8603e.
  cf5b8b200c.
  75de70a431.
  dff2f7b960.
  cf925bb688.
  ffd1363c0e.
  87a2cafb20.
  ffe259d6f2.

content/en/docs/tasks/configure-pod-container/share-process-namespace.md

@@ -11,7 +11,7 @@ weight: 160
 
 {{% capture overview %}}
 
-{{< feature-state state="stable" for_k8s_version="v1.17" >}}
+{{< feature-state state="beta" >}}
 
 This page shows how to configure process namespace sharing for a pod. When
 process namespace sharing is enabled, processes in a container are visible
@@ -27,6 +27,9 @@ include debugging utilities like a shell.
 
 {{< include "task-tutorial-prereqs.md" >}} {{< version-check >}}
 
+Process Namespace Sharing is a **beta** feature that is enabled by default. It
+may be disabled by setting `--feature-gates=PodShareProcessNamespace=false`.
+
 {{% /capture %}}
 
 {{% capture steps %}}