video device: update unique_id on iOS

Change-Id: I723629cfab93861e9759da5eda06de220f5cf544

src/media/video/iosvideo/video_device_impl.cpp

@@ -157,6 +157,7 @@ VideoDeviceImpl::getDeviceParams() const
 
     params.name = name;
     params.input = name;
+    params.unique_id = name;
     params.channel = 0;
     params.pixel_format = "nv12";
     params.width = size_.first;