I didn't go to any service center, but my point is ,this sound is very normal as the camera setup has an OIS lens (means a moving lens inside the camera housing).
Cameras with OISwill make some noise when its shaken. In old devices(when OIS was first introduced by SAMSUNG) this issue was clearly mentioned in the device user manual. SAMSUNG says the lens assembly is freely movable in the camera housing and thats the reason for this noise, also they have mentioned that, while the camera is not in use, the lens may not be in the center of the camrea glass, but it automatcally alligns to the center once the camera is working. If there is not much noise then you dont need to be worried.
The sound is due to the Camera Lens Barrel required to operate the Auto Focus function. If your device supports an Auto Focus function, the Camera module lens unit will be suspended over the image sensor. The autofocus adjusts by moving the lens unit up and down over the image sensor. This helps the Auto Focus speed and accuracy and also reduces battery usage. The camera module is fitted with a 'Stopper' to limit the lens movement within the camera module - when the lens and stopper touch (by shaking your device). a noise may occur. This is a normal operation of the camera. The sound made may differ slightly by device types and models.
