[FIX] account: fix drag and drop on journals

When trying to drop an invoice on a journal on the journal dashboard,
it fails with a message "Could not upload files". The issue is that
commit 6f95be6884 changed a CSS class
where the upload functionality depended on, making it fail.

This commit fixes this issue by adapting the CSS selector of the upload
field.

task-3496997

closes odoo/odoo#134965

Signed-off-by: Laurent Smet (las) <las@odoo.com>

addons/account/static/src/components/bills_upload/bills_upload.js

@@ -96,7 +96,7 @@ export class AccountDropZone extends Component {
     }
 
     onDrop(ev) {
-        const selector = '.account_file_uploader.o_input_file.o_hidden';
+        const selector = '.account_file_uploader.o_input_file';
         // look for the closest uploader Input as it may have a context
         let uploadInput = ev.target.closest('.o_drop_area').parentElement.querySelector(selector) || document.querySelector(selector);
         let files = ev.dataTransfer ? ev.dataTransfer.files : false;