{containerapp} az containerapp update fix list secret value for populate

[Greedygre]

---

fix issue: #6712
This checklist is used to make sure that common guidelines for a pull request are followed.

Related command

'az containerapp update': fix bug for populating secret value with --yaml

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

️✔️Non Breaking Changes

[azure-client-tools-bot-prd]

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

[yonzhan]

containerapp

[Greedygre]

Hi @zhoxing-ms
Could you please help to review and approve this PR? Thanks!

[azclibot]

[Release] Update index.json for extension [ containerapp ] : https://dev.azure.com/azclitools/internal/_build/results?buildId=87919&view=results