update ar translation
update ar translation

Change-Id: If53be0bc2abaab1472d560a94f6abe4d7c727963

HotChalk/canvas-lms,sfu/canvas-lms,venturehive/canvas-lms,SwinburneOnline/canvas-lms,grahamb/canvas-lms,sfu/canvas-lms,matematikk-mooc/canvas-lms,dgynn/canvas-lms,dgynn/canvas-lms,djbender/canvas-lms,HotChalk/canvas-lms,venturehive/canvas-lms,djbender/canvas-lms,instructure/canvas-lms,djbender/canvas-lms,grahamb/canvas-lms,fronteerio/canvas-lms,matematikk-mooc/canvas-lms,HotChalk/canvas-lms,fronteerio/canvas-lms,sfu/canvas-lms,matematikk-mooc/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,grahamb/canvas-lms,dgynn/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,djbender/canvas-lms,sfu/canvas-lms,dgynn/canvas-lms,grahamb/canvas-lms,sfu/canvas-lms,venturehive/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,grahamb/canvas-lms,sfu/canvas-lms,SwinburneOnline/canvas-lms,SwinburneOnline/canvas-lms,fronteerio/canvas-lms,HotChalk/canvas-lms,fronteerio/canvas-lms,venturehive/canvas-lms,instructure/canvas-lms,SwinburneOnline/canvas-lms,matematikk-mooc/canvas-lms