title: Firebase rules without Firebase authentication
body: <p>I know this is a duplicate question but none of them helped me</p>
  
  <p>I use Firestore for storing little amount of data... which will be deleted after some minutes which contains no personal information. I have my own authentication system for logging users in. The users have read and write permission in the Firestore. The problem is application is in production and I keep getting Firebase warning mail that '<em>Your Cloud Firestore database has insecure rules</em>'.</p>
  
  <p>i have published Firebase rule as</p>
  
  <pre><code>rules_version = '2';
  service cloud.firestore {
    match /databases/{database}/documents {
      match /{document=**} {
        allow read, write: if true;
      }
    }
  }
  </code></pre>
  
  <p>I have gone through many reference and I figured it out that for secure data we have to you it's own authentication. or is there any solution for it..?</p>