Show approve button on Stripe refund payment when submitted

Closes #14599
(grafted from 0359c8ecc314160ac16e60af001b2d3ae1aebd1a)

--HG--
branch : 6.0

modules/account_payment_stripe/payment.py

@@ -868,7 +868,7 @@ class Refund(Workflow, ModelSQL, ModelView):
                     'depends': ['state'],
                     },
                 'approve': {
-                    'invisible': Eval('state') != 'draft',
+                    'invisible': Eval('state') != 'submitted',
                     'icon': 'tryton-forward',
                     'depends': ['state'],
                     },