Without this fix, the partner_bank_id was being reset to False on change of 'company_id'
in the _onchange_purchase_auto_complete method in account.move in the following unit test:
def test_from_purchase_order_invoicing_bank
That's because in commit 9be9766535 we switched to
getting payment method from env.ref('account.account_payment_method_manual_out'), which has
bank_account_required == False by default, while before that we were creating payment method for
which we were explicitly setting bank_account_required as True
Also tag unit test as post_install
