function deviceKeyEvent(keycode, metastate) {
    var data = {
        keycode: keycode
    };

    if (metastate) {
        data.metastate = metastate;
    }

    var requestOptions = {
        path: '/session/:sessionId/appium/device/keyevent',
        method: 'POST'
    };

    return this.requestHandler.create(requestOptions, data);
}
send a key event to the device

@param {Number} keyValue  device specifc key value

@see  https://github.com/appium/appium/blob/master/docs/en/writing-running-appium/other/appium-bindings.md#key-event
@type mobile
@for android