[FIX] pos_sale: override order_line_field

In the _order_line_field function from the pos order line model,
the override doesn't set a default value for session_id in pos_sale.

Now we make sure the override is correct.

closes odoo/odoo#139973

X-original-commit: bb3742fcc82c032d85f6a547ba1ecb8a84819a25
Signed-off-by: Adrien Guilliams (adgu) <adgu@odoo.com>
Signed-off-by: Joseph Caburnay (jcb) <jcb@odoo.com>

addons/pos_sale/models/pos_order.py

@@ -128,7 +128,7 @@ class PosOrderLine(models.Model):
         result['sale_order_origin_id'] = bool(orderline.sale_order_origin_id) and orderline.sale_order_origin_id.read(fields=['name'])[0]
         return result
 
-    def _order_line_fields(self, line, session_id):
+    def _order_line_fields(self, line, session_id=None):
         result = super()._order_line_fields(line, session_id)
         vals = result[2]
         if vals.get('sale_order_origin_id', False):