Update install-kubectl.md (#14072)

Added a step under the sections that guide the user to install the binary using curl on the OS. This is the same format maintained by the other section on this page.

content/en/docs/tasks/tools/install-kubectl.md

@@ -50,6 +50,11 @@ You must use a kubectl version that is within one minor version difference of yo
     ```
     sudo mv ./kubectl /usr/local/bin/kubectl
     ```
+4. Test to ensure the version you installed is up-to-date:
+
+    ```
+    kubectl version
+    ```
 
 ### Install using native package management
 
@@ -120,6 +125,11 @@ If you are on Ubuntu or another Linux distribution that support [snap](https://s
     ```
     sudo mv ./kubectl /usr/local/bin/kubectl
     ```
+4. Test to ensure the version you installed is up-to-date:
+
+    ```
+    kubectl version
+    ```
 
 ### Install with Homebrew on macOS
 
@@ -169,6 +179,11 @@ If you are on macOS and using [Macports](https://macports.org/) package manager,
     To find out the latest stable version (for example, for scripting), take a look at [https://storage.googleapis.com/kubernetes-release/release/stable.txt](https://storage.googleapis.com/kubernetes-release/release/stable.txt).
 
 2. Add the binary in to your PATH.
+3. Test to ensure the version you installed is up-to-date:
+
+    ```
+    kubectl version
+    ```
 
 ### Install with Powershell from PSGallery