Support running Geo on Kubernetes

Geo is not officially supported when running Kubernetes: https://docs.gitlab.com/ee/install/kubernetes/gitlab_chart.html#limitations There is an open issue in the charts project to support this: https://gitlab.com/charts/gitlab/issues/8 . And there is a summary on that issue: https://gitlab.com/charts/gitlab/issues/8#note_97097233

Customers have requested this feature:

• https://gitlab.my.salesforce.com/0016100001Eo2H5
• https://gitlab.zendesk.com/agent/tickets/106725

We need to confirm if the summary on the related ticket is correct, and determine what work needs to be done.