title: Unresolved reference: FlutterActivity
body: <p>I was researching a bit about writing native code in flutter. On opening the MainActivity.kt file in android I faced these issues.</p>
  <p><a href="https://i.stack.imgur.com/oSsX0.png" rel="noreferrer"><img src="https://i.stack.imgur.com/oSsX0.png" alt="enter image description here" /></a></p>
  <p>On highlighting the error it showed 'Unresolved reference: FlutterActivity'.</p>
  <p>Can someone please help me to fix this issue ?</p>
  <p>Thankyou in advance.</p>