Skip role with isAdmin when save custom permission

Indeed, currently the module exports permissions also for is_admin roles. But such roles have always all the permissions, so we should not pollute their configs with unneeded permissions.

Tested the MR and it works.

+1 for this. When saving a custom admin only permission, the module was deleting all the other permissions in user.role.administrator.yml, and replacing with only the permissions for the field in question.

Thanks for the patch, it seems to fix the issue.

It works for me as well.