Kubernetes executor should allow mountPropagation

Description

Kubernetes executor allows host path volumes. This won't work if the host path uses automount. Adding the volumeMount option "mountPropagation: HostToContainer" solves this.

Proposal

Allow "mountPropogation" as an option, in a similar way to how host_path is supplied.

Links to related issues and merge requests / references

Edited by Chris Reynolds