update ar translation
update ar translation

Change-Id: I22b06d22a0b7a5b6620eca87b04889e865622e27
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/236799
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