Add domain field to Auto DevOps application setting
Auto DevOps includes an application setting that allows instance admins to enable the feature instance wide. In order to have Auto Review App and Auto Deploy working, a domain has to be specified. At the moment, it is possible only at project-level, so enabling Auto DevOps at instance level is not enough to make it fully functional.
Proposal / Design
Add an instance setting that specifies domain at the same way we have it at project-level.
It is an inputbox similar to what we have in CI/CD > Settings (see #38175 (comment 53324166)), but with the following text:
Specify a domain to use by default for every project's Auto Review Apps and Auto Deploy stages.
- Allow configuring Auto DevOps when using charts: https://gitlab.com/charts/charts.gitlab.io/issues/103