update ar translation
update ar translation

Change-Id: I377897b7d6ecc1ad85a852ba7f0930dd1bb3f0dc
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/283999
Tested-by: Service Cloud Jenkins <9144042a601061f88f1e1d7a1753ea3e2972119d@instructure.com>

sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms