title: component is not unmounting react-native
body: <p>In my code I have a problem with unmount a component. I am using drawer-navigator and when i navigating between drawer-screens the previous screen is not dying and when i open that screen again everything is still there.</p>
  <p>But i want to re-render or unmount and mount the component again when i navigate between drawer-screens. Is there a way for that? Or how can i make my component unmount manually? I know there is a lot of question about this but i couldn't find that i want.</p>
  <p>My react native version is 0.63</p>