az containerapp cannot installed automatically.

> ### `az feedback` auto-generates most of the information requested below, as of CLI version 2.0.62

**Related command**

I am using the latest azure cli. When I first use this command `az containerapp`

The result is below. It makes me confused and the containerapp extension is not installed automatically.

```
$ az containerapp
'containerapp' is misspelled or not recognized by the system.
Did you mean 'container' ?

Examples from AI knowledge base:
https://aka.ms/cli_ref
Read more about the command in reference docs
```

But when I type `az containerapp -h`. I get prompt to install containerapp extension.

```
$ az containerapp -h
The command requires the extension containerapp. Do you want to install it now? The command will continue to run after the extension is installed. (Y/n): Y
Run 'az config set extension.use_dynamic_install=yes_without_prompt' to allow installing extensions without prompt.
The installed extension 'containerapp' is in preview.
```

**Describe the bug**

**To Reproduce**

**Expected behavior**

From doc https://learn.microsoft.com/en-us/cli/azure/containerapp?view=azure-cli-latest. The doc said when user type "az containerapp" it will automatically install containerapp extension. But actually, it doesn't.

I expect the azure-cli could support automatically install containerapp extension as doc said.

**Environment summary**

```
$ az --version
azure-cli 2.43.0

core 2.43.0
telemetry 1.0.8

Extensions:
containerapp 0.3.16
deploy-to-azure 0.2.0

Dependencies:
msal 1.20.0
azure-mgmt-resource 21.1.0b1

Python location '/opt/az/bin/python3'
Extensions directory '/home/ruowan/.azure/cliextensions'

Python (Linux) 3.10.8 (main, Dec 2 2022, 06:08:21) [GCC 7.5.0]

Legal docs and information: aka.ms/AzureCliLegal

Your CLI is up-to-date.

```

**Additional context**

Start by reproducing `az containerapp` and `az containerapp -h` on the reported Azure CLI version, then trace the dynamic extension installation path for the `containerapp` command. Compare the behavior with the linked containerapp documentation; done means the documented invocation installs or prompts for the extension consistently.

Written by the indexing model from the issue text.