fix issue when restoring a deleted quiz with student submissions

fixes CNVS-15098, CNVS-15079

test plan:
  - as a teacher
    - create a quiz
    - publish the quiz

  - as a student
    - take the quiz

  - as a teacher
    - delete the quiz
    - attempt to restore the quiz
    - the quiz should restore successfully

Change-Id: I5111e5beeb6debbb43a587689251e2fb62a8d3bc
Reviewed-on: https://gerrit.instructure.com/40159
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Ahmad Amireh <ahmad@instructure.com>
QA-Review: Trevor deHaan <tdehaan@instructure.com>
Product-Review: Derek DeVries <ddevries@instructure.com>