Changing option in multiple choice multiple correct question type unchecks correct answer boxes

When changing the All or Nothing or Right Less Wrong option for Multiple Choice Multiple Correct question types, the Correct Answer boxes are unchecked and need to be re-checked before saving. Steps to reproduce:

1. Login as Instructor
2. Add the Tests and Quizzes tool
3. Create a new exam
4. Add a Multiple Choice question type
5. Select the Multiple Choice Multiple Select radio button
6. Add a question and possible answers
7. Check the Correct Answer box next to a couple of those answers
8. Save the question
9. Click the Edit link next to the question you just created
10. Change the option under multiple correct to All or Nothing or Right Less Wrong

Expected result:
The previously selected correct answers remain checked

Actual Result :
The correct answers are now unchecked and need to be rechecked