title: Keyboard exits fullscreen mode on older Android versions
body: <p>I was trying to use fullscreen in my app, but I noticed that on devices with android 8.1 (API 27), when the user opens a keyboard the app exits fullscreen mode and doesn't comeback unless the ui is rebuild, does anyone have a solution?</p>
  <p>I also tested on Android 7.1 (API 25) and the problem is easier to deal with, the only thing that doesn't come back to fullscreen is the top bar, but still, the code below only works flawless on new androids (API 28 +)</p>
  <p>Code:</p>
  <pre><code>void main() {
    runApp(MaterialApp(home: MyApp()));
  }
  
  class MyApp extends StatelessWidget {
    @override
    Widget build(BuildContext context) {
      SystemChrome.setEnabledSystemUIOverlays([]);
      return Scaffold(
        body: SafeArea(
            child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Flexible(flex: 1, child: Text('Fullscreen test')),
            Flexible(
              flex: 1,
              child: TextFormField(
                controller: TextEditingController(),
              ),
            ),
            Flexible(flex: 1, child: SizedBox())
          ],
        )),
      );
    }
  }
  </code></pre>
  <p><a href="https://i.stack.imgur.com/ZbN0r.gif" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ZbN0r.gif" alt="Exemple on Android 8.1" /></a></p>