[FIX] rating: count and average

In an app using rating (e.g. eLearning), get 3 ratings:
- A 5-star review
- A 3-star review
- A 0-star review

The average is 2.5 stars, while it should be 4 stars.

This happens because the 0-star review is taken into account in the
average computation, while it shouldn't. Indeed, zero star means no
review.

We apply the same login than:
https://github.com/odoo/odoo/blob/0028a602bea6a48aaa2747127ec075394732b324/addons/rating/models/rating_mixin.py#L205

opw-2290617

closes odoo/odoo#54279

X-original-commit: 4f7981f80fb55ab4bf8b30d137e45b4fda4013cd
Signed-off-by: Nicolas Martinelli (nim) <nim@odoo.com>

addons/rating/models/rating_mixin.py

@@ -3,7 +3,7 @@
 from datetime import timedelta
 
 from odoo import api, fields, models, tools
-from odoo.addons.rating.models.rating import RATING_LIMIT_SATISFIED, RATING_LIMIT_OK
+from odoo.addons.rating.models.rating import RATING_LIMIT_SATISFIED, RATING_LIMIT_OK, RATING_LIMIT_MIN
 from odoo.osv import expression
 
 
@@ -68,7 +68,7 @@ class RatingMixin(models.AbstractModel):
     @api.depends('rating_ids.res_id', 'rating_ids.rating')
     def _compute_rating_stats(self):
         """ Compute avg and count in one query, as thoses fields will be used together most of the time. """
-        domain = self._rating_domain()
+        domain = expression.AND([self._rating_domain(), [('rating', '>=', RATING_LIMIT_MIN)]])
         read_group_res = self.env['rating.rating'].read_group(domain, ['rating:avg'], groupby=['res_id'], lazy=False)  # force average on rating column
         mapping = {item['res_id']: {'rating_count': item['__count'], 'rating_avg': item['rating']} for item in read_group_res}
         for record in self: