code: public void processGcmMessage(String channel, String action, String message) {
      if (channel == null || !containsDefaultPushCallback(channel)) {
        channel = AVOSCloud.getApplicationId();
        if (action != null) {
          sendBroadcast(channel, message, action);
        } else {
          sendNotification(channel, message);
        }
      }
    }
docs: 处理 GCM 的透传消息
  @param channel
  @param action
  @param message