Views List Sort allows views to be sorted by a list field's allowed values. This is useful if the allowed values are stored in a non-alphabetical order, but you want to present your view results in the same order as your allowed values are stored.
- Enable the module.
- Add a "List (text)" sort field to your view.
- In the sort field settings, set "Sort by allowed values" to "yes".
Drupal 8 port of https://www.drupal.org/project/views_list_sort.