title: Firestore: how to perform a query with inequality / not equals
body: <p>I want select from Firestore collection just articles written NOT by me.
  <br>Is it really so hard?</p>
  <blockquote>
  <p>Every article has field &quot;owner_uid&quot;.</p>
  </blockquote>
  <p>Thats it: <br>I JUST want to write equivalent to <code>&quot;select * from articles where uid&lt;&gt;request.auth.uid&quot;</code></p>
  <p><strong>TL;DR: solution found already:</strong> usages for languages/platforms: <a href="https://firebase.google.com/docs/firestore/query-data/queries#kotlin+ktx_5" rel="noreferrer">https://firebase.google.com/docs/firestore/query-data/queries#kotlin+ktx_5</a></p>