Symbolize keys to fix question banks fixup
Symbolize keys to fix question banks fixup

refs: LS-1692
flag = none

Test plan:
- Import https://pcraighill.test.instructure.com/courses/221
- View /courses/:course_id/question_banks
- Verify that there are broken questions
- Apply fixup /courses/:course_id/question_banks?fixup_quiz_math_questions=1
- Verify that all questions are fixed

Change-Id: I43ec60fc07ce5f1e4336f1ad64261640ec16f7d1
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/254786
Tested-by: Service Cloud Jenkins <9144042a601061f88f1e1d7a1753ea3e2972119d@instructure.com>
Reviewed-by: Jeremy Stanley <b3f594e10a9edcf5413cf1190121d45078c62290@instructure.com>
QA-Review: Nate Armstrong <619b324efbf5f7848de055bdc8bef4c0dd7c8ef5@instructure.com>
Product-Review: Nate Armstrong <619b324efbf5f7848de055bdc8bef4c0dd7c8ef5@instructure.com>

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