Use Helm 2.7.2 for GitLab Managed Apps

What does this MR do?

Start using Helm Tiller 2.7.2 for Gitlab managed apps

Are there points in the code the reviewer needs to double check?

This MR / Issue does not cover upgrading Helm Tiller installations. We only need the new clusters created with SSL certs to start using Tiller 2.7.2 on the server. Upgrading Tiller and applications will be in future work.

Why was this MR needed?

To avoid an issue with certs when we start using SSL Auth for Tiller

Screenshots (if relevant)

TO DO

• Test creating new cluster with Helm 2.7.2 and install apps with Helm 2.7.2
• Test with existing cluster with Helm 2.7.0, and then install apps with Helm 2.7.2
• [-] helm init --upgrade to Helm 2.7.2

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• [-] Documentation created/updated
• [-] API support added
• Tests added for this feature/bug
• Conforms to the code review guidelines
  • [-] Has been reviewed by a UX Designer
  • [-] Has been reviewed by a Frontend maintainer
  • Has been reviewed by a Backend maintainer
  • [-] Has been reviewed by a Database specialist
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• [-] Conforms to the database guides
• If you have multiple commits, please combine them into a few logically organized commits by squashing them
• [-] Internationalization required/considered
• End-to-end tests pass (package-and-qa manual pipeline job)

What are the relevant issue numbers?

Closes #49830 (closed)