Update OIDC metadata section with mtls_endpoint_aliases

[jsoveral]

Added information about mtls_endpoint_aliases in OIDC metadata for Mutual-TLS Client Authentication.

[prmerger-automator[bot]]

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[learn-build-service-prod[bot]]

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[ttorble]

@cephalin

Can you review the proposed changes?

IMPORTANT: When the changes are ready for publication, adding a #sign-off comment is the best way to signal that the PR is ready for the review team to merge.

#label:"aq-pr-triaged" @MicrosoftDocs/public-repo-pr-review-team