title: Remove navigation stack for login screen after user login
body: <p>I am new to React Native. I am so confused about navigation stack.</p>
  
  <p>Here is my code.</p>
  
  <pre><code>const AppNavigator = () =&gt; {
    return (
      &lt;NavigationContainer&gt;
        &lt;Stack.Navigator&gt;
          &lt;Stack.Screen name="Login" component={LoginScreen} options={{ title: 'login' }}/&gt;
          &lt;Stack.Screen name="Home" component={HomeScreen} options={{ title: 'home' }}/&gt;
        &lt;/Stack.Navigator&gt;
      &lt;/NavigationContainer&gt;
    );
  };
  </code></pre>
  
  <p>Users will see the login screen once they run this app.
  And here is LogInScreen.</p>
  
  <pre><code>const LogInScreen = ({ navigation }) =&gt; {
    return (
      &lt;View style={{ flex: 1, alignItems: 'center', justifyContent: 'center' }}&gt;
        &lt;Button 
          title="google login"
          onPress={() =&gt; 
            navigation.navigate('Home')
          }
        /&gt;
      &lt;/View&gt;
    );
  };
  </code></pre>
  
  <p>Users is going to see home screen after they clicked login button.
  But the problem is they still can see back button in home screen.
  After log in , it's not necessary to show login screen to users.
  Hence, I need to reset stack to remove back button in home screen. </p>