[Fix][16.0] Fix model_create_multi in generic_mixin_uuid

[YuriyGural]

In addon generic_mixin need to change file generic_mixin_uuid.py:

Replace def create(self, vals)... on

@api.model_create_multi
def create(self, vals_list):
    for vals in vals_list:
        vals_uuid = vals.get(self._generic_mixin_uuid_field_name, '/')
        if not vals_uuid or vals_uuid == '/':
            # If uuid is not provided in vals, or is equeal to '/', then we
            # have to generate new uuid
            vals[self._generic_mixin_uuid_field_name] = (
                self._generic_mixin_uuid__generate_new())
    return super(GenericMixinUUID, self).create(vals_list)