support datadog agent uds filepath

[clarafu]

Port over commit to add datadog agent uds filepath field to release/7.4.x branch

Fixes https://ci.concourse-ci.org/teams/main/pipelines/release/jobs/k8s-check-helm-params/builds/3?vars.version=%227.4.x%22

Contributor Checklist

• [ ] Variables are documented in the README.md
• [ ] Which branch are you merging into?
  • master is for changes related to the current release of the concourse/concourse:latest image and should be good to publish immediately
  • dev is for changes related to the next release of Concourse (aka unpublished code on master in concourse/concourse)

Reviewer Checklist

This section is intended for the core maintainers only, to track review progress. Please do not fill out this section.

• [ ] Code reviewed
• [ ] Topgun tests run
• [ ] Back-port if needed
• [ ] Is the correct branch targeted? (master or dev)