GitLab Shell's sshd configuration does not observe `service.internalPort`

Origin

The following discussion from !1249 (merged) should be addressed:

• @balasankarc started a discussion: (+1 comment)

  @twk3 @WarheadsSE So, I think this MR is ready for another review. I've added a "Development decisions" section in the MR description along with a sample additional settings file which got me to spin up a GitLab Shell pod without errors. Few things to note

  1. service.externalPort is not "required" because it will take the value of the internalPort. Also, we don't expect users to normally change this. I am not opposed to making this also a required setting from a practical perspective, but it is technically not needed.
  2. I have skipped validation for global values entirely since that should come from the root values.yaml file. We can add a validation for that as a next iteration.

Details

The sshd always runs on 2222 (from configmap!) despite containerPort: {{ .Values.service.internalPort }} in the Deployment template. 🐛