[FIX] stock_account: reinforce search domain in test

The account move search was not enough specific to retreive only one
account move. The following `assert` sometimes failed because of this.

This commit reinforce to search to get only one account move

closes odoo#158355

Opw: runbot error 60338
X-original-commit: 78518f5
Signed-off-by: Arnold Moyaux (arm) <arm@odoo.com>
Signed-off-by: William Henrotin (whe) <whe@odoo.com>

Author: Whenrow

addons/stock_account/tests/test_stockvaluation.py

@@ -4064,6 +4064,9 @@ def test_manual_revaluation_statement(self):
         revaluation = revaluation_form.save()
         revaluation.action_validate_revaluation()
 
-        account_move = self.env['account.move'].search([('journal_id', '=', revaluation.account_journal_id.id)])
+        account_move = self.env['stock.valuation.layer'].search([
+            ('product_id', '=', self.product1.id),
+            ('stock_move_id', '=', False),
+        ]).account_move_id
 
         self.assertEqual(account_move.line_ids[0].name, 'OdooBot changed stock valuation from  15.0 to 25.0 - [prda] Product A')