title: Why orderByChild does not sort in AngularFire for Realtime database?
body: <p>I'm trying to order an acccount list using <code>orderByChild</code> using <code>dateCreated</code> field, but the return list(response) is not sorted by <code>dateCreated</code></p>
  <pre><code> this.angularDb.list('accounts', ref =&gt; ref
          .orderByChild('dateCreated').startAt(0).limitToFirst(10)
          ).valueChanges()
          .subscribe(response =&gt; {
              for (let item of response) {
                this.tableData.push(item);
              }
       
           }, error =&gt; {
              console.log(error);
           });
      
    }
  </code></pre>
  <p>Any idea what I'm doing wrong? I cannot find any source solve this issue</p>