fix rending boolean value on quiz show screens
fix rending boolean value on quiz show screens

closes QO-727
flag=none

test plan:
- Nav to a quiz show view as a teacher.
- Observe that no boolean true/false value is rendered
  beneath the due date table.

- The rest of this:  is copied from the tp for g/257468, that was
  where the bug was introduced and we need to make sure that
  fix is still working.
- create a classic quiz with "Show one question at a time", and
  "Lock questions after answering" enabled
- preview and submit the quiz multiple times
- make sure everything works.

- submit the quiz as students, everythibng should work well

Change-Id: I00c2fd184bcff49ec254aa312184829e179d3b6b
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/258106
Tested-by: Service Cloud Jenkins <9144042a601061f88f1e1d7a1753ea3e2972119d@instructure.com>
QA-Review: Mark McDermott <20dd8ba615f2257ea7254f93d6f30ae11aa4f904@instructure.com>
Product-Review: Stephen Kacsmark <90aaf30f5583a54f0f3cdbd115e37bda3a251932@instructure.com>
Reviewed-by: Bryan Petty <33564f6eff3d808d3eaaa056a1631fdcde5faed6@instructure.com>

instructure/canvas-lms,sfu/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms