[22353] Document new transmit_algorithms_as_legacy on builtin security plugins (backport #974)

[mergify]

Description

This PR adds documentation for the new properties added in eProsima/Fast-DDS#5450

@Mergifyio backport 3.1.x 3.0.x 2.14.x 2.10.x

Contributor Checklist

• Commit messages follow the project guidelines.
• Code snippets related to the added documentation have been provided.
• Documentation tests pass locally.
• Applicable backports have been included in the description.

Reviewer Checklist

• The PR has a milestone assigned.
• The title and description correctly express the PR's purpose.
• Check contributor checklist is correct.
• CI passes without warnings or errors.

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This is an automatic backport of pull request #974 done by [Mergify](https://mergify.com).

[mergify]

Cherry-pick of cc95496 has failed:

On branch mergify/bp/2.14.x/pr-974
Your branch is up to date with 'origin/2.14.x'.

You are currently cherry-picking commit cc95496.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:
	modified:   docs/fastdds/security/access_control_plugin/access_control_plugin.rst

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   code/DDSCodeTester.cpp
	both modified:   code/XMLTester.xml
	both modified:   docs/fastdds/property_policies/security.rst
	both modified:   docs/fastdds/security/auth_plugin/auth_plugin.rst

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally