Quiz submit all and finish confirmation modal not announcing when it appears

Issue
Context changes - When the user clicks the submit all and finish button the confirmation modal is not announcing that it has appeared to the user.

Standard Level*
WCAG 2 3.3.2 (A) http://www.w3.org/WAI/WCAG20/quickref/#qr-minimize-error-cues

Impact
Serious

Example Link
http://next-qa/mod/quiz/summary.php?attempt=1305

Test Steps

1. Login as a student
2. navigate to course
3. Click on quiz
4. Click attempt quiz button
5. Click the next button until the end of the quiz
6. Click the submit all and Finnish button with screen reader on and hear no announcement that a popup has been opened.