update msdp dos Signed-off-by:li-bo-boblove<boblove.libo@huawei.com>

Signed-off-by: Nli-bo-boblove <boblove.libo@huawei.com>

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. If this parameter is not passed, all callbacks associated with the specified event in the process will be unregistered. |
+| callback | Callback:\<[ActivityResponse](#activityresponse)>  | No  | Callback used to receive reported data, If the callback parameter is not passed or the type passed is undefined, all callbacks associated with the specified event in the process will be unregistered. |
 
 **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，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。  |
+| 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参数或者传递的类型是undefined，会移除该进程下订阅该类型得所有callback。  |
 
 **示例：**