[FIX] point_of_sale : allow edit to amount on done payment after reload

When you reload the pos (F5), this.payment_terminal is undefined.
And you can update the amount even if the payment is done.

closes odoo/odoo#81546

X-original-commit: 2e10f33511ced41f296e0f65d2d042f4e041cacb
Signed-off-by: Quentin Lejeune (qle) <qle@odoo.com>
Signed-off-by: Masereel Pierre <pim@odoo.com>

addons/point_of_sale/static/src/js/Screens/PaymentScreen/PaymentScreen.js

@@ -81,8 +81,9 @@ odoo.define('point_of_sale.PaymentScreen', function (require) {
             }
             if (!this.selectedPaymentLine) return; // do nothing if no selected payment line
             // disable changing amount on paymentlines with running or done payments on a payment terminal
+            const payment_terminal = this.selectedPaymentLine.payment_method.payment_terminal;
             if (
-                this.payment_interface &&
+                payment_terminal &&
                 !['pending', 'retry'].includes(this.selectedPaymentLine.get_payment_status())
             ) {
                 return;