Enable testing against ACR

[adityapatwardhan]

PR Summary

Enable testing against ACR instance. The ACR instance is in an internal subscription and connection is done via a service connection in AzDO. The az token is used to set a secret in secret vault, which is used to register the repository.

PR Context

PR Checklist

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• [ ] Summarized changes
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• Breaking changes
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  • [ ] [Documentation needed]()
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• User-facing changes
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  • [ ] N/A or can only be tested interactively
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  • [ ] Make sure you've added a new test if existing tests do not effectively test the code changed
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[alerickson]

Resolves #1512