fix: bring parity to DC* region naming to match aks cli for prometheus metrics extension

[bragi92]

---

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

Related command

az k8s-extension create --name azuremonitor-metrics --cluster-name <Arc-cluster-name> --resource-group <Arc-resource-group> --cluster-type connectedClusters --extension-type Microsoft.AzureMonitor.Containers.Metrics

az k8s-extension update --name azuremonitor-metrics --resource-group <Arc-resource-group> --cluster-name <Arc-cluster-name> --cluster-type connectedClusters

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? (pip install wheel==0.30.0 required)
• My extension version conforms to the Extension version schema

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.

[github-actions]

The git hooks are available for azure-cli and azure-cli-extensions repos. They could help you run required checks before creating the PR.

Please sync the latest code with latest dev branch (for azure-cli) or main branch (for azure-cli-extensions).
After that please run the following commands to enable git hooks:

pip install azdev --upgrade
azdev setup -c <your azure-cli repo path> -r <your azure-cli-extensions repo path>

[github-actions]

CodeGen Tools Feedback Collection

Thank you for using our CodeGen tool. We value your feedback, and we would like to know how we can improve our product. Please take a few minutes to fill our codegen survey

[bragi92]

@bavneetsingh16 , @anagg929 Can you please help in reviewing this PR?

I see some build failures but I don't think they are related to my change: