Firmware update: T46S to work with Plantronic Voyager UC [bluetooth]

Yealink T46S firmware used by RingCentral is an older firmware that is not compatible with our user using a Plantronics Voyager UC via Bluetooth connection.

Firmware ver 66.85.0.5 is a newer version which we used to have with Vonage which perfectly works the said headset.

Please test firmware for compatibility.