[FIX] product: count only active pricelists

Problem:
When we are in the form view of a product variant, the smart button "Extra Price" shows the number of pricelists for this variant including the archived ones

Steps to reproduce:
- Install "Sales" app and activate the pricelists
- Create a product and some variants
- Create at least one pricelist for a variant
- Archive at least one of these pricelist
- Go on the form view of the variant and take a look at the smart button which shows the number of pricelists including the archived ones

Cause:
The domain that filters the pricelists doesn't take in consideration whether the pricelist is active

opw-3836973

closes odoo/odoo#160876

Signed-off-by: Axel Trémaudant (axtr) <axtr@odoo.com>

addons/product/models/product_product.py

@@ -304,9 +304,12 @@ class ProductProduct(models.Model):
 
     def _compute_variant_item_count(self):
         for product in self:
-            domain = ['|',
-                '&', ('product_tmpl_id', '=', product.product_tmpl_id.id), ('applied_on', '=', '1_product'),
-                '&', ('product_id', '=', product.id), ('applied_on', '=', '0_product_variant')]
+            domain = [
+                ('pricelist_id.active', '=', True),
+                '|',
+                    '&', ('product_tmpl_id', '=', product.product_tmpl_id.id), ('applied_on', '=', '1_product'),
+                    '&', ('product_id', '=', product.id), ('applied_on', '=', '0_product_variant'),
+            ]
             product.pricelist_item_count = self.env['product.pricelist.item'].search_count(domain)
 
     def _compute_product_document_count(self):