Add istio host in values.yaml

All Submissions:

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• [YES/NO] I have added an explanation of what changes in this merge do and why we should include it?
• [YES/NO] I have updated the documentation accordingly.
• [YES/NO/NA] I have added tests to cover my changes.
• [YES/NO/NA] All new and existing tests passed.
• [YES/NO/NA] My code follows the code style of this project.
• [YES/NO/NA] I ran lint checks locally prior to submission.

What is the current behavior?

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Issue: Remember to link the workitem to this pull request.

What is the new behavior?

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Adding a new host for istio dns value.

Does this introduce a breaking change?

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• [NO]

Any relevant logs, error output, etc?

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(If it’s long, please paste to https://ghostbin.com/ and insert the link here.)

Other information

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