def remove_from_group
      new_group_owner = group_members.earliest
      if new_group_owner.present?
        new_group_owner.update(group_owner_id: nil)
        group_members.update_all(group_owner_id: new_group_owner.id)
      end
      new_group_owner
    end
def remove_from_group
      new_group_owner = group_members.earliest
      if new_group_owner.present?
        new_group_owner.update(group_owner_id: nil)
        group_members.update_all(group_owner_id: new_group_owner.id)
      end
      new_group_owner
    end
Remove from notification group and make a new group owner.

 @return [Notificaion] New group owner instance of the notification group