Purpose of this commit is to allow to make private channels linked to an HR department with an auto subscription. It will ease the use of discussion channels among employees of a given department. Moreover auto subscription is useful to avoid having to manually synchronize channel members and department members. This commit is linked to task ID 1848526 and closes PR #26650 . Co-authored-by: Gert Pellin <gpe@odoo.com> Co-authored-by: Richard Mathot <rim@odoo.com>