resource/gitlab_group: Update the allowable values for default_branch_protection

[numbnp]

Description

Update the allowable values for default_branch_protection according to the documentation
https://docs.gitlab.com/ee/api/groups.html#options-for-default_branch_protection

PR Checklist Acknowledgement

• I acknowledge that all of the following items are true, where applicable:
  • Resource attributes match 1:1 the names and structure of the API resource in the GitLab API documentation.
  • Examples are updated with:
    • A *.tf file for the resource/s with at least one usage example
    • A *.sh file for the resource/s with an import example (if applicable)
  • New resources have at minimum a basic test with three steps:
    • Create the resource
    • Update the attributes
    • Import the resource
  • No new //lintignore comments were copied from existing code. (Linter rules are meant to be enforced on new code.)

[github-actions]

Welcome @numbnp 👋

It looks like this is your first submission to the Terraform GitLab Provider! If you haven’t already done so, please make sure you have checked out our CONTRIBUTING.md guide to make sure your contribution has all the necessary elements in place for a successful approval.

Thanks again, and welcome to the community! 😃

[armsnyder]

Thanks for the fix!

[github-actions]

This functionality has been released in v3.15.0 of the Terraform GitLab Provider. Please see the Terraform documentation on provider versioning or reach out if you need any assistance upgrading.

For further feature requests or bug reports with this functionality, please create a new GitHub issue. Thank you!