[FIX] hr: activity type responsible on hr plans

fine-tuning of bf8a9af1ac549be830bec28c88eb1c565b591941

- Employees > Configuration > Activity Planning > Plans and ensure the
  activities have different responsible;
- Create a new Employee, assign a Manager (a different user then the one
  connected, you can assign Marc Demo for example);
- Click launch plan.

Before this commit, the activity type responsible is ignored and the
responsible for all activities is the connected user.

Now, the responsible for the activities are assigned taking into account
the activity type configuration.

opw-2265631

closes odoo/odoo#54054

X-original-commit: 0f4ec369dccdf25aed259ae97b5cc8973a1a8c5a
Signed-off-by: Jorge Pinna Puissant (jpp) <jpp@odoo.com>

addons/hr/wizard/hr_plan_wizard.py

@@ -31,6 +31,7 @@ class HrPlanWizard(models.TransientModel):
                     user_id=responsible.id
                 )
                 activity._onchange_activity_type_id()
+                activity.user_id = responsible.id
 
         return {
             'type': 'ir.actions.act_window',