[DBM] Update documented defaults

[ian28223]

What does this PR do?

Documents conditional default values for options.replication and options.extra_status_metrics

Motivation

• https://github.com/DataDog/integrations-core/pull/10541
• ZD 1753288

Additional Notes

Review checklist (to be filled by reviewers)

• [ ] Feature or bugfix MUST have appropriate tests (unit, integration, e2e)
• [ ] Changelog entries must be created for modifications to shipped code
• [ ] Add the qa/skip-qa label if the PR doesn't need to be tested during QA.
• [ ] If you need to backport this PR to another branch, you can add the backport/<branch-name> label to the PR and it will automatically open a backport PR once this one is merged