show 'show feedback' button for canvadocs
show 'show feedback' button for canvadocs

fixes CNVS-25272

Test plan:
  * disable canvadocs
  * enable crocodoc
  * submit a pdf assignment
  * the student submission page should show "view feedback"
  * disable crocodoc
  * enable canvadocs without annotations
  * submit a pdf assignment
  * the student submission page should show "preview"
  * enable canvadocs with annotations
  * submit a pdf assignment
  * the student submission page should show "view feedback"

Change-Id: I33766d825ee1ee7eb573b90c738919b887335696
Reviewed-on: https://gerrit.instructure.com/68036
Tested-by: Jenkins
Reviewed-by: Spencer Olson <7cc0890d6f1f70810a023e7173eca5724d6c8e49@instructure.com>
QA-Review: Jason Carter <976bfc4bed0555ff96b3266aea18e7b17a9d471c@instructure.com>
Product-Review: Cameron Matheson <1d572acbfa68c7c6e541c7b840d6b622e5c0dc91@instructure.com>

matematikk-mooc/canvas-lms,roxolan/canvas-lms,grahamb/canvas-lms,sfu/canvas-lms,HotChalk/canvas-lms,fronteerio/canvas-lms,grahamb/canvas-lms,sfu/canvas-lms,roxolan/canvas-lms,redconfetti/canvas-lms,dgynn/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,matematikk-mooc/canvas-lms,grahamb/canvas-lms,snehakachroo1/LSI_replica,SwinburneOnline/canvas-lms,fronteerio/canvas-lms,roxolan/canvas-lms,snehakachroo1/LSI_replica,redconfetti/canvas-lms,venturehive/canvas-lms,sfu/canvas-lms,dgynn/canvas-lms,venturehive/canvas-lms,sfu/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,grahamb/canvas-lms,dgynn/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,HotChalk/canvas-lms,dgynn/canvas-lms,SwinburneOnline/canvas-lms,redconfetti/canvas-lms,venturehive/canvas-lms,snehakachroo1/LSI_replica,snehakachroo1/LSI_replica,SwinburneOnline/canvas-lms,djbender/canvas-lms,djbender/canvas-lms,grahamb/canvas-lms,redconfetti/canvas-lms,matematikk-mooc/canvas-lms,venturehive/canvas-lms,djbender/canvas-lms,fronteerio/canvas-lms,sfu/canvas-lms,HotChalk/canvas-lms,fronteerio/canvas-lms,djbender/canvas-lms,roxolan/canvas-lms,instructure/canvas-lms,matematikk-mooc/canvas-lms,HotChalk/canvas-lms,sfu/canvas-lms,SwinburneOnline/canvas-lms