Im am getting the following error when attempting to implement a native plugin in Unity. I have this plugin working in both a standalone Android application as well as a VR implementation so I think this is a specific ARCore permission issue. I am not familiar with how Tango is implemented with regard to ARCore:
W/tango: permission_handler.cc:76 The application 'com.midtablestudios.'ApplicationName'' does not have permission to use the Tango 'Dataset Read/Write' capabilities. To ask the user of your app for this permission, invoke the Tango Android permissions intent for 'Dataset Read/Write'.
Looks like this was a permission issue with Preview 1 (see image). It appears that that it would only grant the first permission in the permissions array (odd!) and since the camera is required for ARCore, that's the only permission you could register. Preview 2 lets you pass permissions as strings directly without this array setup.
ex: AndroidPermissionsManager.RequestPermission("android.permission.WRITE_EXTERNAL_STORAGE")
AndroidPermissionManager.cs_ScreenShot