Add preview tag for new commands

[Juliehzl]

---

This checklist is used to make sure that common guidelines for a pull request are followed.

Related command

General Guidelines

• Have you run azdev style <YOUR_EXT> locally? (pip install azdev required)
• Have you run python scripts/ci/test_index.py -q locally?

For new extensions:

• My extension description/summary conforms to the Extension Summary Guidelines.

About Extension Publish

There is a pipeline to automatically build, upload and publish extension wheels.
Once your pull request is merged into main branch, a new pull request will be created to update src/index.json automatically.
You only need to update the version information in file setup.py and historical information in file HISTORY.rst in your PR but do not modify src/index.json.

[azure-client-tools-bot-prd]

⚠️Azure CLI Extensions Breaking Change Test

⚠️containerapp

rule	cmd_name	rule_message	suggest_message
⚠️ 1003 - CmdPropAdd	containerapp env list-usages	cmd containerapp env list-usages added property is_preview
⚠️ 1003 - CmdPropAdd	containerapp list-usages	cmd containerapp list-usages added property is_preview
⚠️ 1003 - CmdPropAdd	containerapp show-custom-domain-verification-id	cmd containerapp show-custom-domain-verification-id added property is_preview

[azure-client-tools-bot-prd]

Hi @Juliehzl,
Please write the description of changes which can be perceived by customers into HISTORY.rst.
If you want to release a new extension version, please update the version in setup.py as well.

[azure-client-tools-bot-prd]

Hi @Juliehzl,
Since the current milestone time is less than 7 days, this pr will be reviewed in the next milestone.

[yonzhan]

Thank you for your contribution! We will review the pull request and get back to you soon.

[Juliehzl]

/azp run

[azure-pipelines]

Commenter does not have sufficient privileges for PR 6697 in repo Azure/azure-cli-extensions

[Seris370]

LGTM