用Nash/Unity导出ADF到Tango存储卡- ADF写入权限被拒绝

我正在使用Unity 5和Tango，并试图获得区域学习样本代码(Nash)以将ADF导出到SD卡。我得到的logcat错误是:

I/tango_client_api(  195): Tango Service: saveAreaDescriptionMetadata, internal status 0
W/tango_client_api(  195): The application 'com.projecttango.experiments.unityarealearning' has no ADF import/export permissions. Instead of calling import/export through the Tango Service API, call the import/export Android intent.
I/tango_client_api(  195): Tango Service: exportAreaDescription, internal status -6
E/tango   (  195): TangoServer.cc:309 Export Area Description has no permission.
E/tango_client_api( 9873): TangoErrorType TangoService_exportAreaDescription(const char*, const char*): Internal Error: Could not export the ADF: 95f406fa-f24f-41bc-9355-5abd0db68c14 into folder: /sdcard/defaultArea.
I/Unity   ( 9873): PoseProvider.ExportAreaDescription() Could not export area description: 95f406fa-f24f-41bc-9355-5abd0db68c14
I/Unity   ( 9873):  
I/Unity   ( 9873): (Filename: ./artifacts/generated/common/runtime/UnityEngineDebug.gen.cpp Line: 56)
I/Unity   ( 9873): 

似乎我必须复制这个基于意图的导出和导入权限，而不仅仅是ADF加载和保存(参见:https://developers.google.com/project-tango/apis/java/java-user-permissions)

但是在c# Unity中，我不知道如何。