Include default branch configuration in export/import
Summary
Hello, I'm trying to export/import a project with a specific default branch but when I do this the default branch change. (Also have the same problem with group-level custom templates).
I listed the issue as a bug since in the description of the export say all project configurations are exported except integrations.

Steps to reproduce
- In a project, create a branch with a name later in the alphabetical order then the default branch.
- Export the project
- Import the project
Example Project
Project to export: https://gitlab.com/Calvinaud/project-to-export/-/branches Project imported: https://gitlab.com/Calvinaud/imported-project/-/branches
What is the current bug behavior?
The default branch can change.
What is the expected correct behavior?
The default branch doesn't change.
Relevant logs and/or screenshots
Branch before import:
Branch after import:

Output of checks
This bug happens on Gitlab.com (in 14.4.0) (also happens in a self-managed instance on 14.3.0)
Possible fixes
Not sure if it's the correct track but it look like in this file: https://gitlab.com/gitlab-org/gitlab/-/blob/master/lib/gitlab/import_export/project/import_export.yml that there is no reference of a property "default branch".
Workaround
Change the default_branch in the project settings after the migration is completed