swap icons in course settings for Export/Import

fixes CNVS-12184

test plan
 - go to course settings
 - export should be a down arrow
 - import should be an up arrow

Change-Id: I1160729bf6f8c02b54b1d8f2a630ba2afeb92792
Reviewed-on: https://gerrit.instructure.com/36407
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Jeremy Stanley <jeremy@instructure.com>
Product-Review: Rob Orton <rob@instructure.com>
QA-Review: Rob Orton <rob@instructure.com>