update ar translation
update ar translation

Change-Id: I365d1ee098af392a2dc1780b6caf00dc671834a9

SwinburneOnline/canvas-lms,fronteerio/canvas-lms,roxolan/canvas-lms,grahamb/canvas-lms,venturehive/canvas-lms,SwinburneOnline/canvas-lms,SwinburneOnline/canvas-lms,grahamb/canvas-lms,roxolan/canvas-lms,fronteerio/canvas-lms,sfu/canvas-lms,roxolan/canvas-lms,djbender/canvas-lms,grahamb/canvas-lms,grahamb/canvas-lms,djbender/canvas-lms,grahamb/canvas-lms,sfu/canvas-lms,HotChalk/canvas-lms,fronteerio/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,roxolan/canvas-lms,HotChalk/canvas-lms,venturehive/canvas-lms,HotChalk/canvas-lms,sfu/canvas-lms,venturehive/canvas-lms,sfu/canvas-lms,fronteerio/canvas-lms,venturehive/canvas-lms,djbender/canvas-lms,HotChalk/canvas-lms,SwinburneOnline/canvas-lms,djbender/canvas-lms