fix multicam_streaming test to validate 2 devices connected with usb3.2 are available.
fix multicam_streaming test to validate 2 devices connected with usb3.2 are available.

IntelRealSense/librealsense,IntelRealSense/librealsense,IntelRealSense/librealsense,IntelRealSense/librealsense,IntelRealSense/librealsense,IntelRealSense/librealsense,IntelRealSense/librealsense,IntelRealSense/librealsense,IntelRealSense/librealsense