update ar translation
update ar translation

Change-Id: Ic2549a518b79edd9447fd543f5c9c15e9784e245
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/280542
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