添加撤回/删除推送通知。在iOS已经实现，在android平台需要实现

src/main/java/cn/wildfirechat/push/PushMessage.java

@@ -24,7 +24,7 @@ public class PushMessage {
     public String voipDeviceToken;
     public boolean isHiddenDetail;
     public String language;
-
+    public long messageId;
 
     public String getSender() {
         return sender;