获取房间自定义信息

https://xxxxxx/v4/live_engine_http_srv/get_room_metadata?
sdkappid=88888888&identifier=admin&usersig=xxx&random=99999999&contenttype=json

{
  "RoomId": "live-room",
  "Keys":["key1", "key2"] //如果为空数组表示获取该房间的所有的自定义信息，否则就是获取指定Key列表的自定义信息
}

{
  "ActionStatus": "OK",
  "ErrorInfo": "",
  "ErrorCode": 0,
  "RequestId": "Id-8c9858f01e954611ae2d4c1b1ed7d583-O-Seq-52720",
  "Response": {
        "Metadata": [
            {
                "Key": "key1",
                "Value": "value1"
            },
            {
                "Key": "key2",
                "Value": "value2"
            }
        ]
  }
}