update ar translation
update ar translation

Change-Id: Iff65b3c789b3869e0f713512232af7d087aac5a4
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/268330
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