Stop requiring gitaly storage with name "default"

Problem to solve

Currently in my installation i have got multiple storages with gitaly[1-n] names that have similar configurations and they are located on VMs named same way. But suddenly I need forced to create gitaly named default cause it's currently required.

Actually I don't understand why default storage is required.

Intended users

Selfhosted gitlab admins

Further details

Proposal

Permissions and Security

Documentation

Testing

What does success look like, and how can we measure that?

Gitalies naming is fully controlled by user