Tests canceling a bluetooth device request prompt after a device option is prompted.
deviceRequestPrompted: {
    devices : [
        [0] : {
            id : <string>
            name :
        }
    ]
    id : <string>
}
cancelPrompt: {
    id : <number>
    result : {
    }
    sessionId : <string>
}
navigator.bluetooth.requestDevice: {
    className : DOMException
    description : NotFoundError: User cancelled the requestDevice() chooser.
    objectId : <string>
    subtype : error
    type : object
}