[25536] Fix some warnings in generated code (backport #593)

[MiguelCompany]

Description

This is a manual backport of #593. It is basically a rebase of its branch removing the commit that updates the IDL parser submodule.

@Mergifyio backport 3.3.x

Contributor Checklist

• Commit messages follow the project guidelines.
• N/A: Tests that thoroughly check the new feature have been added/Regression tests checking the bug and its fix have been added; the added tests pass locally
• N/A: New feature has been documented/Current behavior is correctly described in the documentation.
• 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.
• Check CI results: changes do not issue any warning.
• Check CI results: failing tests are unrelated with the changes.

[cferreiragonz]

LGTM. CI passed in eProsima/Fast-DDS#6479

[mergify]

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[MiguelCompany]

@Mergifyio backport 3.3.x

[mergify]

backport 3.3.x

✅ Backports have been created

Details

• #596 [25536] Fix some warnings in generated code (backport #593) (backport #594) has been created for branch 3.3.x but encountered conflicts

Cherry-pick of 49cb136 has failed:

On branch mergify/bp/3.3.x/pr-594
Your branch is up to date with 'origin/3.3.x'.

You are currently cherry-picking commit 49cb136.
  (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:   src/main/java/com/eprosima/fastdds/idl/templates/TypesCdrAuxHeaderImpl.stg

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   src/main/java/com/eprosima/fastcdr/idl/templates/FastCdrCommon.stg
	both modified:   src/main/java/com/eprosima/fastdds/idl/templates/eprosima.stg

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