Have you tried taking the pads out on that side, to see if it stops, whilst driving on axle stands? Obviously , don't press the brake pedal until you have put the pads back in
, visually inspect in case a rust fragment has got bedded in the brake pads, also are there any fresh score marks on the disc?
If you still don't solve it, I know it involves a fair bit of work, but the next step is to remove the drive shaft from the center of the disc assembly. Spin the disc hub by hand and see if you can feel the grating. if you can, then push the the brake pads away from the disc and see if it stops. If it stops carefully inspect the pads as a metal part maybe slightly wrong and chafing. However there should be a corresponding shiny witness mark. Failing that, If the grating is still there and you've checked the ABS sensor and ABS ring. Then the only 2 places the grating can be coming from is the wheel bearing or around the area the hub fits into the assembly.
If everything is fine when the drive shaft has been removed, then perhaps the outer CV joint needs packing with CV grease, the inner CV on these cars are also known to fail, but usually the outer joint is the culprit. Because it hasn't enough grease in it due to having been replaced, and the amount of grease in the grease sachet, that's provided with the replacement boot isn't enough . You will have to undo the outer CV rubber boot clip and inspect. By the way,inspecting the outer CV joint and re packing the joint with CV grease can be carried out whilst the car is on stands and still attached to the Hub assembly. Make sure you clean all surrounding areas before undoing the CV rubber clip, to prevent grit /dirt getting into the CV joint,