android: Fix edge-to-edge layout issues with settings and app selection

Using FrameLayout for the settings instead of the recommended
FragmentContainerView because the latter makes handling insets more
complicated (fitsSystemWindows doesn't work as the fragment is responsible
for handling insets but how that should work with PreferenceFragmentCompat
is unclear).

Fixes: 2404b2bee6 ("android: Apply UI changes for edge-to-edge views in Android 15+")

src/frontends/android/app/src/main/java/org/strongswan/android/ui/SelectedApplicationsActivity.java

@@ -20,7 +20,9 @@ import android.content.Intent;
 import android.os.Bundle;
 import android.view.MenuItem;
 
+import org.strongswan.android.R;
 import org.strongswan.android.data.VpnProfileDataSource;
+import org.strongswan.android.utils.Utils;
 
 import androidx.activity.OnBackPressedCallback;
 import androidx.annotation.Nullable;
@@ -38,8 +40,9 @@ public class SelectedApplicationsActivity extends AppCompatActivity
 	protected void onCreate(@Nullable Bundle savedInstanceState)
 	{
 		super.onCreate(savedInstanceState);
+		setContentView(R.layout.selected_applications_activity);
 		WindowCompat.enableEdgeToEdge(getWindow());
-		WindowCompat.setDecorFitsSystemWindows(getWindow(), true);
+		Utils.applyWindowInsetsAsMarginsForLists(findViewById(R.id.fragment_container));
 
 		ActionBar actionBar = getSupportActionBar();
 		actionBar.setDisplayHomeAsUpEnabled(true);
@@ -59,7 +62,7 @@ public class SelectedApplicationsActivity extends AppCompatActivity
 		if (mApps == null)
 		{
 			mApps = new SelectedApplicationsListFragment();
-			fm.beginTransaction().add(android.R.id.content, mApps, LIST_TAG).commit();
+			fm.beginTransaction().add(R.id.fragment_container, mApps, LIST_TAG).commit();
 		}
 	}
 

src/frontends/android/app/src/main/java/org/strongswan/android/ui/SelectedApplicationsListFragment.java

@@ -34,6 +34,7 @@ import org.strongswan.android.R;
 import org.strongswan.android.data.VpnProfileDataSource;
 import org.strongswan.android.ui.adapter.SelectedApplicationEntry;
 import org.strongswan.android.ui.adapter.SelectedApplicationsAdapter;
+import org.strongswan.android.utils.Utils;
 
 import java.util.ArrayList;
 import java.util.Collections;
@@ -61,6 +62,9 @@ public class SelectedApplicationsListFragment extends ListFragment implements Me
 		super.onViewCreated(view, savedInstanceState);
 		requireActivity().addMenuProvider(this, getViewLifecycleOwner());
 
+		getListView().setClipToPadding(false);
+		Utils.applyWindowInsetsAsPaddingForLists(getListView());
+
 		final boolean readOnly = getActivity().getIntent().getBooleanExtra(VpnProfileDataSource.KEY_READ_ONLY, false);
 		getListView().setChoiceMode(readOnly ? ListView.CHOICE_MODE_NONE : ListView.CHOICE_MODE_MULTIPLE);
 

src/frontends/android/app/src/main/java/org/strongswan/android/ui/SettingsActivity.java

@@ -19,6 +19,8 @@ package org.strongswan.android.ui;
 import android.os.Bundle;
 import android.view.MenuItem;
 
+import org.strongswan.android.R;
+
 import androidx.appcompat.app.AppCompatActivity;
 import androidx.core.view.WindowCompat;
 
@@ -29,14 +31,18 @@ public class SettingsActivity extends AppCompatActivity
 	protected void onCreate(Bundle savedInstanceState)
 	{
 		super.onCreate(savedInstanceState);
+		setContentView(R.layout.settings_activity);
 		WindowCompat.enableEdgeToEdge(getWindow());
-		WindowCompat.setDecorFitsSystemWindows(getWindow(), true);
 
 		getSupportActionBar().setDisplayHomeAsUpEnabled(true);
 
-		getSupportFragmentManager().beginTransaction()
-							.replace(android.R.id.content, new SettingsFragment())
-							.commit();
+		if (savedInstanceState == null)
+		{
+			getSupportFragmentManager().beginTransaction()
+				.setReorderingAllowed(true)
+				.add(R.id.fragment_container, SettingsFragment.class, null)
+				.commit();
+		}
 	}
 
 	@Override

src/frontends/android/app/src/main/java/org/strongswan/android/ui/TrustedCertificateImportActivity.java

@@ -41,7 +41,6 @@ import androidx.activity.result.contract.ActivityResultContracts;
 import androidx.appcompat.app.AlertDialog;
 import androidx.appcompat.app.AppCompatActivity;
 import androidx.appcompat.app.AppCompatDialogFragment;
-import androidx.core.view.WindowCompat;
 import androidx.fragment.app.FragmentTransaction;
 
 public class TrustedCertificateImportActivity extends AppCompatActivity

src/frontends/android/app/src/main/java/org/strongswan/android/ui/TrustedCertificatesActivity.java

@@ -33,7 +33,6 @@ import org.strongswan.android.logic.TrustedCertificateManager;
 import org.strongswan.android.logic.TrustedCertificateManager.TrustedCertificateSource;
 import org.strongswan.android.security.TrustedCertificateEntry;
 import org.strongswan.android.ui.CertificateDeleteConfirmationDialog.OnCertificateDeleteListener;
-import org.strongswan.android.utils.Utils;
 
 import java.security.KeyStore;
 

src/frontends/android/app/src/main/res/layout/selected_applications_activity.xml

@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+    Copyright (C) 2025 Tobias Brunner
+
+    Copyright (C) secunet Security Networks AG
+
+    This program is free software; you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by the
+    Free Software Foundation; either version 2 of the License, or (at your
+    option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
+
+    This program is distributed in the hope that it will be useful, but
+    WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+    or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+-->
+<androidx.fragment.app.FragmentContainerView
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/fragment_container"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent" />

src/frontends/android/app/src/main/res/layout/settings_activity.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+    Copyright (C) 2025 Tobias Brunner
+
+    Copyright (C) secunet Security Networks AG
+
+    This program is free software; you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by the
+    Free Software Foundation; either version 2 of the License, or (at your
+    option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
+
+    This program is distributed in the hope that it will be useful, but
+    WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+    or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+-->
+<FrameLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/fragment_container"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:fitsSystemWindows="true" />