Show Docker image ID in job's log

Merged username-removed-378947 requested to merge log-docker-image-id into master

What does this MR do?

It adds logging Docker image ID.

Why was this MR needed?

Docker image name does not uniquely identify an image.

Does this MR meet the acceptance criteria?

  • [ ] Documentation created/updated
  • Tests
    • [ ] Added for this feature/bug
    • All builds are passing
  • Branch has no merge conflicts with master (if you do - rebase it please)

What are the relevant issue numbers?

Closes https://gitlab.com/gitlab-org/gitlab-ci-multi-runner/issues/2169