补充sysCap能力标识

Signed-off-by: NPaDaBoo <xuejianwu@huawei.com>

zh-cn/application-dev/reference/apis/js-apis-data-preferences.md

@@ -13,6 +13,8 @@
 import data_Preferences from '@ohos.data.preferences'
 ```
 
+## 系统能力
+SystemCapability.DistributedDataManager.Preferences.Core
 
 ## 权限
 

zh-cn/application-dev/reference/apis/js-apis-data-storage.md

@@ -13,6 +13,8 @@
 import dataStorage from '@ohos.data.storage'
 ```
 
+## 系统能力
+SystemCapability.DistributedDataManager.Preferences.Core
 
 ## 权限