title: react-native footer appears above keyboard on android
body: <p>I have this react-navigation TabNavigator component and the problem is when the form input is focused, the TabNavigator footer appears on top of keyboard and it happens only on Android. How to solve this ? I have tried adding styles such as 
   position: 'absolute',
   bottom: 0
  in tabBarOptions.
  Here is my TabNavigator</p>
  
  <pre><code>export const AuthTaber = TabNavigator(
    {
      Signin: { screen: Signin },
      Signup: { screen: Signup }
    },
    {
      tabBarPosition: 'bottom',
      swipeEnabled: true,
      animationEnabled: true,
      lazy: true,
      tabBarComponent: props =&gt; {
        return(
          &lt;Footer&gt;
            &lt;FooterTab style={Style.bgBlack}&gt;
              &lt;Button
                vertical
                // active={props.navigationState.index === 0}
                onPress={() =&gt; props.navigation.navigate('Signin')}
                &gt;
                &lt;Text style={Style.white}&gt;Sign In&lt;/Text&gt;
              &lt;/Button&gt;
              &lt;Button
                vertical
                // active={props.navigationState.index === 1}
                onPress={() =&gt; props.navigation.navigate('Signup')}
                &gt;
                &lt;Text style={Style.white}&gt;Sign Up&lt;/Text&gt;
              &lt;/Button&gt;
            &lt;/FooterTab&gt;
          &lt;/Footer&gt;
        );
      }
    }
  );
  </code></pre>