Update jquery progress bar css for high contrast
Update jquery progress bar css for high contrast

This is a jquery widget, and the _variables.scss file changed
here is not high-contrast aware.  This change will affect  any
jquery widget with class including .ui-state-active

closes: ADMIN-2441

test plan:
  - follow recreate steps in the ticket
  > expect the progress bar to be electric blue with a gradient
  > expect high-contrast progress bar to be the dark blue with no
    gradient

testing tip: if you're testing locally, kill delayed_jobs, now the group
creation will never progress. in devTools inspect the progress par and
in the <div class="ui-progress-bar-value>, set it's style="width: 0%" to
something larger.  In another tab, you can open /profile/settings and
toggle high-contrast mode and refresh the test tab.

Change-Id: Ib2b22a4322aad6193213c574907c75b0198572fb
Reviewed-on: https://gerrit.instructure.com/183248
Tested-by: Jenkins
Reviewed-by: Jon Willesen <0321efbc0acf6204eb6035acb1d418838b450d08@instructure.com>
QA-Review: Daniel Sasaki <ae19fabf7fe19dff310008c9b6a4d2ec84d311d8@instructure.com>
Product-Review: Daniel Sasaki <ae19fabf7fe19dff310008c9b6a4d2ec84d311d8@instructure.com>

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