Customer feedback | az network bastion rdp | `auth-type` has incomplete information

### Describe the bug

This GitHub issue is being created by UUF `https://aka.ms/UUFTriageApp?pageviewid=86e82778-95ee-3db8-8574-2d34168fb6f1` and resulting azDO [#350886](https://dev.azure.com/msft-skilling/Content/_workitems/edit/350886).
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The customer is wanting to know the allowed values for the `--auth-type` parameter. This information is missing from the parameter description, and there is no example to help fill in the gap.

### Request to engineering
1 - Please provide the allowed values for the authentication type for `az network bastion rdp` command
2 - Add an example that uses this parameter

### Customer feedback

**Repo:**

azure-docs-cli

**Title:**
az network bastion | Microsoft Learn

**Verbatim:**
--auth-type

What parameters are there? documentation again incomplete!

**Verbatim Id:**
ce783d11-7db1-ef11-b8e8-00224802bfe1

**Triaged By:**
v-lmanohar@microsoft.com

**Live URL:**
https://learn.microsoft.com/en-us/cli/azure/network/bastion

**GitHub URL:**
https://github.com/MicrosoftDocs/azure-docs-cli/blob/live/latest/docs-ref-autogen/network/bastion.yml

**UUF Triage App Feedback URL:**
https://aka.ms/UUFTriageApp?pageviewid=86e82778-95ee-3db8-8574-2d34168fb6f1

### Related command

az network bastion rdp

### Errors

.

### Issue script & Debug output

.

### Expected behavior

.

### Environment Summary

Azure CLI 2.67.0

### Additional context

_No response_