[14.0][BUG] Restore product default code

[ilyasProgrammer]

Problem: When you delete attributes from product template default_code is not restored.

Versions: 14.0. Looks like it is in master as well.

Steps to reproduce:

1. Create new Product Template.
2. Set default_code. Save.
3. Add attribute with minimum 2 values. Save. Default code is False now.
4. Delete attribute lines from product template. Save. Default code still False.

Expected behavior: default_code must be restored from single related product variant.

Suggestions:

    @api.depends('product_variant_ids', 'product_variant_ids.default_code')
    def _compute_default_code(self):
        unique_variants = self.filtered(lambda template: len(template.product_variant_ids) == 1)
        for template in unique_variants:
            template.default_code = template.product_variant_ids.default_code
        for template in (self - unique_variants):
            template.default_code = False

This method must be triggered after you unarchive first product variant, but it is not.

It can be fixed like this:

class ProductProduct(models.Model):
    _inherit = "product.product"

   def write(self, values):
        res = super().write(values)
        if values.get('active') and values['active']:
            # _compute_default_code is not triggered by default in this case
            self.product_tmpl_id._compute_default_code()
        return res
```

[vava-odoo]

Hi @ilyasProgrammer
Thanks for your report. @Feyensv could you have look?
Cheers