Kubernetes executor - add support for custom initContainer image

Martin Odstrčilíkrequested to merge
martin.odstrcilik/gitlab-runner:kubernetes-executor-custom-init-container-image into master

What does this MR do?

Adds support for custom initContainer image for Kubernetes executor.

Why was this MR needed?

Closes #27098 (closed)

What's the best way to test this MR?

  • Set init_container_image to override default value.

What are the relevant issue numbers?

Merge request reports