Locking invisible quiz in gradebook setup makes it visible (but only on gradebook setup page)

Prerequisites:

1. Create a course
2. Create a quiz

Testing:

1. Before upgrade, log in as an admin and go to the course page
   1. If you have already upgraded then check out the earlier commit:
      • master - git checkout b79f17e609ebec12c7226e119d811e9aa261f38e
      • 3.10 - git checkout 08e8205d6f1599d6e74c287660236f0c6f60f79d
      • 3.9 - git checkout 565bc965b14a28cbe63a15f789a1e40f717a155a
      • 3.8 - git checkout f6eafcae3ef98f14da6286737a88e548017e32fa
   2. If you have the Moodle Developer Kit (MDK) then run - mdk run version.php on the command line.
2. Hide quiz on course page (make sure it is greyed out and marked as 'Hidden from students')
3. Go to gradebook setup page
4. Verify that quiz grade item is greyed out
5. Edit quiz grade item and check 'Locked' checkbox. Save changes
6. Verify that quiz grade item shows as visible on the gradebook.
7. Perform the upgrade
   1. if you performed a check out in step 1 then run the following command:
      • master - git checkout master
      • 3.10 - git checkout MOODLE_310_STABLE
      • 3.9 - git checkout MOODLE_39_STABLE
      • 3.8 - git checkout MOODLE_38_STABLE
   2. Run the upgrade either through the webpage or the command line.
8. Go back to the gradebook and confirm the quiz shows as hidden
9. Confirm the quiz is still shown as hidden on the course homepage.
10. Show the quiz item
11. Repeat #2 - #4