Add support for kerberos to gitlab-rails

What does this MR do?

This MR adds support for Kerberos in the webservice image.

The goal is to introduce support for Kerberos in GitLab's Helm chart. The proposed changes were applied on top of v14.1.2 and tested in production.

Related issues

Relates to gitlab-org/charts/gitlab#2522 (closed)

Implements container needs for gitlab-org/charts/gitlab!2132 (merged)

Checklist

See Definition of done.

For anything in this list which will not be completed, please provide a reason in the MR discussion

Required

• Merge Request Title, and Description are up to date, accurate, and descriptive
• MR targeting the appropriate branch
• MR has a green pipeline on GitLab.com

Expected (please provide an explanation if not completing)

• Test plan indicating conditions for success has been posted and passes -> N/A
• Documentation created/updated -> N/A
• Integration tests added to GitLab QA -> N/A
• The impact any change in container size has should be evaluated -> 30MB were added

/cc @mareo whom I worked with for this MR.