Revert "WIP"

This reverts commit bf3a0c4fb8.

app/src/main/java/one/nem/lacerta/MainActivity.java

@@ -1,32 +1,14 @@
 package one.nem.lacerta;
 
 import androidx.appcompat.app.AppCompatActivity;
-import androidx.fragment.app.FragmentManager;
-import androidx.navigation.NavController;
-import androidx.navigation.fragment.NavHostFragment;
-import androidx.navigation.ui.NavigationUI;
 
 import android.os.Bundle;
 
-import com.google.android.material.bottomnavigation.BottomNavigationView;
-
 public class MainActivity extends AppCompatActivity {
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
-
-        // デバッグ
-        FragmentManager supportFragmentManager = getSupportFragmentManager();
-        NavHostFragment navHostFragment =
-                (NavHostFragment) supportFragmentManager.findFragmentById(R.id.nav_host_fragment);
-        NavController navController = navHostFragment.getNavController();
-        BottomNavigationView bottomNav = findViewById(R.id.nav_view);
-
-        NavigationUI.setupWithNavController(bottomNav, navController);
-
-        // デバッグ
-
     }
 }