Correcting name of concept 'Container Enviorment Variables' (#19279)

* Correcting name of concept 'Container Enviorment Variables'

This page discusses the container environment and container environment variables are part of it. So removing a 'variable' word to make it more correct.

* Correcting references 

Correcting references

* Correcting reference links

Correcting reference links

content/en/docs/concepts/cluster-administration/cluster-administration-overview.md

@@ -44,7 +44,7 @@ Note: Not all distros are actively maintained. Choose distros which have been te
 
 * [Certificates](/docs/concepts/cluster-administration/certificates/) describes the steps to generate certificates using different tool chains.
 
-* [Kubernetes Container Environment](/docs/concepts/containers/container-environment-variables/) describes the environment for Kubelet managed containers on a Kubernetes node.
+* [Kubernetes Container Environment](/docs/concepts/containers/container-environment/) describes the environment for Kubelet managed containers on a Kubernetes node.
 
 * [Controlling Access to the Kubernetes API](/docs/reference/access-authn-authz/controlling-access/) describes how to set up permissions for users and service accounts.
 

content/en/docs/concepts/containers/container-environment.md

@@ -2,7 +2,7 @@
 reviewers:
 - mikedanese
 - thockin
-title: Container Environment Variables
+title: Container Environment
 content_template: templates/concept
 weight: 20
 ---

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

@@ -116,7 +116,7 @@ Events:
 
 {{% capture whatsnext %}}
 
-* Learn more about the [Container environment](/docs/concepts/containers/container-environment-variables/).
+* Learn more about the [Container environment](/docs/concepts/containers/container-environment/).
 * Get hands-on experience
   [attaching handlers to Container lifecycle events](/docs/tasks/configure-pod-container/attach-handler-lifecycle-event/).