title: Calling Toolbar on each Activity
body: <p>My app has a toolbar that should be present on every view. Currently, I do the following in my <code>onCreate()</code> method for each Activity I have:</p>
  
  <pre><code>Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
  setSupportActionBar(toolbar);
  </code></pre>
  
  <p>Does this need to be done in every <code>onCreate()</code> method in every Activity or is there a simpler way? Also, as a side question, how can I implement a "back" feature in the toolbar that takes the user back one action if they click it?</p>