Fix "Submit Assignment" to announce as a button vs a link
Fix "Submit Assignment" to announce as a button vs a link

Fixes: CNVS-38250

test plan:
- using screenreader technology - ensure that the "Submit" or
  "Re-Submit Assignment" button announces as a button vs a link

   - navigate to a course where an assignment needs to be
     completed... listen to how the "Submit" button is read

Change-Id: I0bc9fe9f715dc66e97102eff7a8cb69d10215948
Reviewed-on: https://gerrit.instructure.com/119294
Tested-by: Jenkins
Reviewed-by: Chris Hart <b82b40b84a2f06957ec9caf1768340bd6b929cc4@instructure.com>
QA-Review: Dan Sasaki <ae19fabf7fe19dff310008c9b6a4d2ec84d311d8@instructure.com>
Product-Review: Kyle Follett <3f0dcef4ea7407b413e459a87705152d37b86e63@instructure.com>

sfu/canvas-lms,venturehive/canvas-lms,venturehive/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,djbender/canvas-lms,djbender/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,venturehive/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,djbender/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,djbender/canvas-lms,venturehive/canvas-lms,sfu/canvas-lms,sfu/canvas-lms