Quiz action menu is not keyboard accessible

The action menu on the Edit quiz page is not keyboard accessible, i.e. when it is opened via space or enter the first item in not selected, it is then not possible to tab through the items on the menu in the way it is on blocks and resources.

Reproducible steps

1. Create a new quiz
2. Enter the quiz as an editing teacher
3. Click on the 'Edit quiz' button
4. Tab through the page until the Add action menu is selected
5. Press enter or space to open the action menu

Notice that no items in the action menu is selected.

It is possible to access the 'a random question' option using the cursor keys, however the 'a new question' and 'from question bank' options cannot be selected via the keyboard.