k8s follow-up - Image build support

[davidferlay]

Context

• Followup of k8s support which introduces container.runtime: kubernetes

Observed

• Image build is not supported yet. The image must exist in the available container registry

Expected

• Would be great to add support of building image when using k8s
• It may be useful to define a remote image registry and related credentials as args/options
• If remote registry is not defined, local registry could be used (same as with docker runtime)