Add Defend for Containers to k8s manifests

[mjwolf]

What does this PR do?

Add the required capabilities to use Defend for Containers integration to the k8s manifest files, as comments.

This will help users set up the Defend for Containers integration, by providing more information on the customization that needs to be done to the agent DaemonSet manifest to get the integration to run properly.

This is the same content which is in the agent Daemonset manifest in other stack versions which support D4C.

Why is it important?

This will help users more easily set up the D4C integration

Checklist

• I have read and understood the pull request guidelines of this project.
• 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
• I have added an entry in ./changelog/fragments using the changelog tool
• I have added an integration test or an E2E test

Disruptive User Impact

None

[mjwolf]

/test

[elasticmachine]

💔 Build Failed

• Buildkite Build
• Commit: 7a7e32f

Failed CI Steps

• x86_64:sudo: deb
• x86_64:sudo: deb

History

• 💔 Build #32506 failed 7ba035b
• 💔 Build #32505 failed b81c8f7
• 💔 Build #32504 failed b81c8f7
• 💔 Build #32501 failed d067780
• 💔 Build #32293 failed dab935f

cc @mjwolf