title: Refresh previous screen on goBack()
body: <p>I am new to React Native. How can we refresh/reload previous screen when returning to it by calling <code>goBack()</code>?</p>
  
  <p>Lets say we have 3 screens A, B, C:</p>
  
  <pre><code>A -&gt; B -&gt; C
  </code></pre>
  
  <p>When we run <code>goBack()</code> from screen C it goes back to screen B but with old state/data. How can we refresh it? The constructor doesn't get called 2nd time.</p>