Merge "Send the only song in queue as now playing song when get item attributes of now playing"

  DEVICE_VLOG(2) << __func__ << ": media_id=\"" << media_id << "\"";

  SongInfo info;

  if (song_list.size() == 1) {

    DEVICE_VLOG(2)

        << __func__

        << " Send out the only song in the queue as now playing song.";

    info = song_list.front();

  } else {

    for (const auto& temp : song_list) {

      if (temp.media_id == media_id) {

        info = temp;

      }

    }

  }

  auto attributes_requested = pkt->GetAttributesRequested();

  if (attributes_requested.size() != 0) {