VpnService: Move it to a backends package

It should be split into two pieces: configuration file management
(loading/saving/renaming/deleting) and calling into wg-quick via
RootShell. The configuration file management part should then go
back into the main package. This is in preparation for adding
additional backends based on wg(8) and wireguard-go.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

app/src/main/AndroidManifest.xml

@@ -12,6 +12,11 @@
         android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
         android:theme="@android:style/Theme.Material.Light.DarkActionBar">
+
+        <activity
+            android:name=".AddActivity"
+            android:label="@string/add_activity_title"
+            android:parentActivityName=".ConfigActivity" />
         <activity android:name=".ConfigActivity">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
@@ -19,10 +24,6 @@
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
-        <activity
-            android:name=".AddActivity"
-            android:label="@string/add_activity_title"
-            android:parentActivityName=".ConfigActivity" />
         <activity
             android:name=".SettingsActivity"
             android:label="@string/settings">
@@ -44,12 +45,13 @@
             <intent-filter>
                 <action android:name="android.service.quicksettings.action.QS_TILE" />
             </intent-filter>
+
             <meta-data
                 android:name="android.service.quicksettings.ACTIVE_TILE"
                 android:value="true" />
         </service>
         <service
-            android:name=".VpnService"
+            android:name=".backends.VpnService"
             android:exported="false" />
     </application>
 

app/src/main/java/com/wireguard/android/BaseConfigActivity.java

@@ -8,6 +8,7 @@ import android.content.ServiceConnection;
 import android.os.Bundle;
 import android.os.IBinder;
 
+import com.wireguard.android.backends.VpnService;
 import com.wireguard.config.Config;
 
 /**

app/src/main/java/com/wireguard/android/BaseConfigFragment.java

@@ -3,6 +3,7 @@ package com.wireguard.android;
 import android.app.Fragment;
 import android.os.Bundle;
 
+import com.wireguard.android.backends.VpnService;
 import com.wireguard.config.Config;
 
 /**

app/src/main/java/com/wireguard/android/BootCompletedReceiver.java

@@ -4,6 +4,8 @@ import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
 
+import com.wireguard.android.backends.VpnService;
+
 public class BootCompletedReceiver extends BroadcastReceiver {
 
     @Override

app/src/main/java/com/wireguard/android/ConfigActivity.java

@@ -8,6 +8,7 @@ import android.os.Bundle;
 import android.view.Menu;
 import android.view.MenuItem;
 
+import com.wireguard.android.backends.VpnService;
 import com.wireguard.config.Config;
 
 /**

app/src/main/java/com/wireguard/android/ConfigEditFragment.java

@@ -14,6 +14,7 @@ import android.view.ViewGroup;
 import android.view.inputmethod.InputMethodManager;
 import android.widget.Toast;
 
+import com.wireguard.android.backends.VpnService;
 import com.wireguard.android.databinding.ConfigEditFragmentBinding;
 import com.wireguard.config.Config;
 

app/src/main/java/com/wireguard/android/ConfigListFragment.java

@@ -13,6 +13,7 @@ import android.widget.AbsListView;
 import android.widget.AdapterView;
 import android.widget.ListView;
 
+import com.wireguard.android.backends.VpnService;
 import com.wireguard.android.bindings.ObservableMapAdapter;
 import com.wireguard.android.databinding.ConfigListFragmentBinding;
 import com.wireguard.config.Config;

app/src/main/java/com/wireguard/android/ConfigListPreference.java

@@ -4,6 +4,8 @@ import android.content.Context;
 import android.preference.ListPreference;
 import android.util.AttributeSet;
 
+import com.wireguard.android.backends.VpnService;
+
 import java.util.Set;
 
 /**

app/src/main/java/com/wireguard/android/QuickTileService.java

@@ -13,6 +13,7 @@ import android.preference.PreferenceManager;
 import android.service.quicksettings.Tile;
 import android.service.quicksettings.TileService;
 
+import com.wireguard.android.backends.VpnService;
 import com.wireguard.config.Config;
 
 @TargetApi(Build.VERSION_CODES.N)

app/src/main/java/com/wireguard/android/backends/RootShell.java

@@ -1,4 +1,4 @@
-package com.wireguard.android;
+package com.wireguard.android.backends;
 
 import android.content.Context;
 import android.util.Log;

app/src/main/java/com/wireguard/android/backends/VpnService.java

@@ -1,4 +1,4 @@
-package com.wireguard.android;
+package com.wireguard.android.backends;
 
 import android.app.Service;
 import android.content.ComponentName;
@@ -14,6 +14,7 @@ import android.preference.PreferenceManager;
 import android.service.quicksettings.TileService;
 import android.util.Log;
 
+import com.wireguard.android.QuickTileService;
 import com.wireguard.android.bindings.ObservableSortedMap;
 import com.wireguard.android.bindings.ObservableTreeMap;
 import com.wireguard.config.Config;
@@ -45,11 +46,6 @@ public class VpnService extends Service
     private static final String TAG = "VpnService";
 
     private static VpnService instance;
-
-    public static VpnService getInstance() {
-        return instance;
-    }
-
     private final IBinder binder = new Binder();
     private final ObservableTreeMap<String, Config> configurations = new ObservableTreeMap<>();
     private final Set<String> enabledConfigs = new HashSet<>();
@@ -57,6 +53,10 @@ public class VpnService extends Service
     private String primaryName;
     private RootShell rootShell;
 
+    public static VpnService getInstance() {
+        return instance;
+    }
+
     /**
      * Add a new configuration to the set of known configurations. The configuration will initially
      * be disabled. The configuration's name must be unique within the set of known configurations.
@@ -406,11 +406,11 @@ public class VpnService extends Service
     }
 
     private class ConfigUpdater extends AsyncTask<Void, Void, Boolean> {
-        private Config knownConfig;
         private final Config newConfig;
         private final String newName;
         private final String oldName;
         private final Boolean shouldConnect;
+        private Config knownConfig;
 
         private ConfigUpdater(final Config knownConfig, final Config newConfig,
                               final Boolean shouldConnect) {

app/src/main/res/layout/config_list_item.xml

@@ -5,7 +5,7 @@
 
         <import type="android.graphics.Typeface" />
 
-        <import type="com.wireguard.android.VpnService" />
+        <import type="com.wireguard.android.backends.VpnService" />
 
         <variable
             name="key"