update ar translation
update ar translation

Change-Id: Icb800f271563b27df57313d30c8415945ef75d6d
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/280679
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