Oculus Go - Deleting file from persistentDataPath when UnityWebRequest abort

I'm trying to delete a file in Go's persistentDataPath directory if the download has been aborted on quitting the application
I've tried both OnApplicationQuit and OnDestroy methods which work fine in the Unity Editor and it's persistentDataPath. For example

public void OnDestroy()
    {
    if (FileExists == 0)
        {
            uwr.Abort();
            File.Delete(Application.persistentDataPath + "/" + videoFileName);
        }
   }

But when quitting the app on the Go, the partly downloaded file does not get removed. I've got Write Permisson set to external in Settings.
OnApplicationPause also deleted the file successfully when the Go is in pause mode. 
Just wondering if there's another method specifically for the Go and/or Android when quitting the application