fixed 0b8c653 from https://gitee.com/shimmer-5880/docs/pulls/23571

补充修改文管子系统文件相关开发文档
Signed-off-by: Nfengjq <fengjunqing@huawei.com>

zh-cn/application-dev/file-management/dev-user-file-manager.md

@@ -24,6 +24,7 @@ OpenHarmony预置了FileManager文件管理器。系统应用开发者也可以
    import fileExtensionInfo from '@ohos.file.fileExtensionInfo';
    import { Filter } from '@ohos.file.fs';
    import common from '@ohos.app.ability.common';
+   import { BusinessError } from '@ohos.base';
    ```
 
    其中fileAccess提供了文件基础操作的API，fileExtensionInfo提供了应用开发的关键结构体。
@@ -45,7 +46,8 @@ OpenHarmony预置了FileManager文件管理器。系统应用开发者也可以
        if (!fileAccessHelperAllServer) {
          console.error("createFileAccessHelper interface returns an undefined object");
        }
-     } catch (error) {    
+     } catch (err) {
+         let error: BusinessError = err as BusinessError;
          console.error("createFileAccessHelper failed, errCode:" + error.code + ", errMessage:" + error.message);
      }
    }

zh-cn/application-dev/file-management/share-app-file.md

@@ -123,6 +123,7 @@
 // xxx.ets
 import fs from '@ohos.file.fs';
 import Want from '@ohos.app.ability.Want';
+import { BusinessError } from '@ohos.base';
 
 function getShareFile() {
   try {