!18470 update msdp callback dos

Merge pull request !18470 from mayunteng/0522

en/application-dev/reference/apis/js-apis-stationary.md

@@ -123,7 +123,7 @@ Unsubscribes from the device status.
 | -------------------- | -------------------------------------------------- | ---- | ---------------------------- |
 | activity  | [ActivityType](#activitytype)  | Yes  | Device status type.             |
 | event  | [ActivityEvent](#activityevent)  | Yes  | Event type.             |
-| callback             | Callback<[ActivityResponse](#activityresponse)\>  | No  | Callback used to receive reported data.   |
+| callback             | Callback<[ActivityResponse](#activityresponse)\>  | No  | Callback used to receive reported data, if the callback parameter is not passed, all callbacks subscribed to this type under this process will be removed.   |
 
 **Example**
 

zh-cn/application-dev/reference/apis/js-apis-stationary.md

@@ -123,7 +123,7 @@ off(activity: ActivityType, event: ActivityEvent, callback?: Callback<Activit
 | -------------------- | -------------------------------------------------- | ---- | ---------------------------- |
 | activity  | [ActivityType](#activitytype)  | 是   | 设备状态能力类型。              |
 | event  | [ActivityEvent](#activityevent)  | 是   | 事件类型。              |
-| callback             | Callback<[ActivityResponse](#activityresponse)\>  | 否   | 回调函数，接收上报状态变化事件。    |
+| callback             | Callback<[ActivityResponse](#activityresponse)\>  | 否   | 回调函数，接收上报状态变化事件，如果没有传递callback参数，会移除该进程下订阅该类型得所有callback。    |
 
 **示例：**