title: How to make Parse.File url's private?
body: <p>I have small app which has a feed section where user can post the data with images and can set post visibility to either public or followers only. For this, I am having Parse Server configured on Heroku with mLab resource and using GCS adapter (Google Cloud Storage) to store images and files. I have written <code>Parse Cloud Function</code> which returns the posts in json format with image or file url, and then I am showing the response in Android App. If there is image attached to post, I am using <code>Glide</code> library to show it using URL returned in the response.</p>
  
  <p>Now my problem is, image's url returned from Parse Server is <strong>public</strong>, and hence anyone can access it from any where and can view the image.</p>
  
  <p>So my question is, how to make parse file url private and can only be accessible by authenticated users only and no one will have access to image only using URL?</p>