title: MaterialDatePicker not working on Android
body: <p>I want to change the date picker of my project to the date picker provided by the Material Components for Android, but it is not working.</p>
  
  <p>This is the code I've tried:</p>
  
  <pre><code>MaterialDatePicker.Builder&lt;Long&gt; builder = MaterialDatePicker.Builder.datePicker();
  
  MaterialDatePicker&lt;Long&gt; picker = builder.build();
  
  picker.show(getSupportFragmentManager(), picker.toString());
  </code></pre>
  
  <p>This is how it looked like:</p>
  
  <p><img src="https://i.stack.imgur.com/7NifA.png" alt="first image"></p>
  
  <p>An this is how it should've looked like:</p>
  
  <p><img src="https://i.stack.imgur.com/z9CaB.png" alt="second image"></p>
  
  <p>Can anybody tell me what's missing?</p>
  
  <p>Thanks</p>