title: React native TextInput not clearing default value when user start Typing
body: <p>According to <a href="https://facebook.github.io/react-native/docs/textinput.html#defaultvalue" rel="nofollow noreferrer">docs</a> on React-Native's website:</p>
  
  <p>defaultValue: Provides an initial value that will change when the user starts typing. Useful for simple use-cases where you do not want to deal with listening to events and updating the value prop to keep the controlled state in sync.</p>
  
  <p>but this is not the case happening in Android API 16. When I tap the textinput component in my app, the default value remains there and is not cleared.
  how to fix this issue? am i doing something wrong?
  my code:</p>
  
  <pre><code>&lt;TextInput style={styles.input} defaultValue='Enter Password'/&gt;
  </code></pre>
  
  <p>how to clear the default value when user starts typing?</p>