Add agent mTLS flags

[michel-laterman]

Add new mTLS flags for 8.13 introduced in elastic/elastic-agent#4007

[github-actions]

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[michel-laterman]

I think we should merge this after the agent changes are in

[mergify]

This pull request does not have a backport label. Could you fix it @michel-laterman? 🙏
To fixup this pull request, you need to add the backport labels for the needed
branches, such as:

• backport-/d./d is the label to automatically backport to the /d./d branch. /d is the digit
  NOTE: backport-skip has been added to this pull request.

[kilfoyle]

LGTM! 👍 Thanks a lot for adding this @michel-laterman