[FIX] account_batch_payment: Payment method on payment not available

Steps to reproduce the bug:

    - Let's consider a journal J with inbound payment methods PM1 and PM2
    - Create an inbound batch payment with Bank = J
    - The default payment method will be PM2, change it to PM1
    - Create a payment P in the batch content (payment_ids)
    - Save

Bug:

    A UserError was raised: The batch must have the same type as the payments it contains.
    because when setting a partner on P the function _compute_payment_method_id defined in module account_check_printing
    was triggered and the first available payment method was set.

opw:2495487

closes odoo/odoo#69683

X-original-commit: 683c3fd267162c93cb278fd903152ac387e6aba6
Signed-off-by: Laurent Smet <smetl@users.noreply.github.com>
Signed-off-by: Simon Goffin (sig) <sig@openerp.com>

addons/account/models/account_payment.py

@@ -378,7 +378,9 @@ class AccountPayment(models.Model):
                 available_payment_methods = pay.journal_id.outbound_payment_method_ids
 
             # Select the first available one by default.
-            if available_payment_methods:
+            if pay.payment_method_id in available_payment_methods:
+                pay.payment_method_id = pay.payment_method_id
+            elif available_payment_methods:
                 pay.payment_method_id = available_payment_methods[0]._origin
             else:
                 pay.payment_method_id = False