Media Device Information
This interface contains information that describes a single media input or output device.
The list of devices obtained by calling AgoraRTC.getDevices is an array of
MediaDeviceInfo objects, one per media device.
Unique ID of the device.
Returns an enumerated value that is "videoinput", "audioinput" or "audiooutput".
DOMString that is a label describing this device (for example "External USB Webcam").
For security reasons, the label field is always blank unless an active media stream exists or the user has granted persistent permission for media device access.