[Wi-Fi] Fix NetworkRequestErrorDialogFragment exception when rotation

When rotating an androidx fragment, it uses default constructor
to instantiate the new fragment instance. Every androidx fragment
should not set private scope to it's default constructor.

Bug: 153824549
Test: make RunSettingsRoboTests ROBOTEST_FILTER=NetworkRequestErrorDialogFragmentTest
Change-Id: Ie1be0e033aa85d37cb4d85193b05beab72d4d8e7

src/com/android/settings/wifi/NetworkRequestErrorDialogFragment.java

@@ -25,6 +25,7 @@ import android.os.Bundle;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.appcompat.app.AlertDialog;
+
 import com.android.settings.R;
 import com.android.settings.core.instrumentation.InstrumentedDialogFragment;
 
@@ -44,10 +45,6 @@ public class NetworkRequestErrorDialogFragment extends InstrumentedDialogFragmen
         return new NetworkRequestErrorDialogFragment();
     }
 
-    private NetworkRequestErrorDialogFragment() {
-        super();
-    }
-
     @Override
     public void onCancel(@NonNull DialogInterface dialog) {
         super.onCancel(dialog);

tests/robotests/src/com/android/settings/wifi/NetworkRequestErrorDialogFragmentTest.java

@@ -17,6 +17,8 @@
 package com.android.settings.wifi;
 
 import static com.google.common.truth.Truth.assertThat;
+
+import static org.junit.Assert.fail;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.spy;
 import static org.mockito.Mockito.verify;
@@ -26,12 +28,15 @@ import android.content.DialogInterface;
 import android.net.wifi.WifiManager.NetworkRequestUserSelectionCallback;
 import android.os.Bundle;
 import android.widget.Button;
+
 import androidx.appcompat.app.AlertDialog;
+
 import com.android.settings.R;
 import com.android.settings.testutils.shadow.ShadowAlertDialogCompat;
 import com.android.settings.wifi.NetworkRequestErrorDialogFragment.ERROR_DIALOG_TYPE;
 import com.android.settingslib.wifi.WifiTracker;
 import com.android.settingslib.wifi.WifiTrackerFactory;
+
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -57,6 +62,15 @@ public class NetworkRequestErrorDialogFragmentTest {
         mFragment.show(mActivity.getSupportFragmentManager(), null);
     }
 
+    @Test
+    public void getConstructor_shouldNotThrowNoSuchMethodException() {
+        try {
+            NetworkRequestErrorDialogFragment.class.getConstructor();
+        } catch (NoSuchMethodException e) {
+            fail("No default constructor for configuration change!");
+        }
+    }
+
     @Test
     public void display_shouldShowTimeoutDialog() {
         AlertDialog alertDialog = ShadowAlertDialogCompat.getLatestAlertDialog();