[shorod]

That noise does not sound like anything that would be caused by a bad brake caliper, a bad u-joint (since your Rav4 doesn't have u joints in the front), or a bad hub. I'd be more inclined to think the issue is a loose brake pad or a pad with a loose shim on it. I'd suggest carefully inspecting the anti-rattle clips to make sure they are correctly installed and not worn out. You could get a brake hardware kit with new anti-rattle clips and slide pins with boots and be done with it.

Since you don't mention a pulsation in the brake pedal or steering wheel I doubt the issue is with the rotor either, but if there was a piece of rust or dirt stuck between the rotor and the hub it could maybe cause a noise like that under light braking, but under heavy braking you'd have a nasty pulsation/vibration in the brake pedal and/or steering wheel.

-Rod