title: Want to create and get server time in application without saving into Firestore database
body: <p>I want to set server time in Firestore database in <code>Long</code> format. I have tried to create timestamp using below code, it seems like it creates just reference of the <code>FieldValue</code>. </p>
  
  <pre><code>val dataMap = HashMap&lt;String, Any&gt;()
  dataMap["createdOn"] = FieldValue.serverTimestamp()
  </code></pre>
  
  <p>Is there any way to create server time and convert it into required format? </p>