fix rendering user content in draft state pages

test plan (draft state enabled):
 * create a page
   - include media comments (audio & video)
 * save the page
 * navigating to the page should show all media comments correctly
   (media comments should not be rendered as video/audio tags)
 * edit the same page
   - add additional media comments
 * save the page
 * navigating to the page should still show all elements correctly
   (specifically looking for anomalies in re-saving)

fixes CNVS-11257

Change-Id: I45db2703719c036a0725dbc25f118eec22dedce8
Reviewed-on: https://gerrit.instructure.com/30656
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Sterling Cobb <sterling@instructure.com>
QA-Review: Matt Fairbourn <mfairbourn@instructure.com>
Reviewed-by: Jeremy Stanley <jeremy@instructure.com>
Product-Review: Jeremy Stanley <jeremy@instructure.com>