[9.4](backport #50119) Update kafka certificates to include SANS

[mergify]

Proposed commit message

This PR updates the certificates used inside kafka container to use SAN's.

Checklist

• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have made corresponding change to the default configuration files
• I have added tests that prove my fix is effective or that my feature works. Where relevant, I have used the stresstest.sh script to run them under stress conditions and race detector to verify their stability.
• I have added an entry in ./changelog/fragments using the changelog tool.

Disruptive User Impact

None

Related issues

• Required for [beatreceivers] Add support for ssl parameters for kafka output elastic-agent#13313

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This is an automatic backport of pull request #50119 done by [Mergify](https://mergify.com).

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