title: Firebase UI is displaying null for displayName under the user object
body: <p>I am using the Firebase UI Web to allow users to signup to my Firebase project. I am then using a cloud function (in Node.js):</p>
  
  <p><code>exports.newUserUpdate = functions.auth.user().onCreate(user =&gt; {})</code></p>
  
  <p>to then send the newly created user an email. When I read in <code>user.displayName</code> or console.log the <code>user</code> object, it displays the <code>displayName</code> as null. This seemingly looks like the <code>displayName</code> was not submitted on the signup.</p>
  
  <p>I am using Firebase UI Web 3.4.1.</p>
  
  <p>Thanks.</p>