Refactor settings top level activities to use fragments.

Added a base class SettingsPreferenceFragment from which the settings activities should
be derived so that they can behave like fragments. It contains some commonly called
utility methods and dialog conversion to DialogFragment.

Some of the top-level activities can be launched directly without the left pane.
Settings.java acts as a proxy activity that contains just that settings fragment without
the left pane.

There are still a lot of second and third level activities that need to be fragmentized.
This is just the first pass to test the 2-pane layout.
diff --git a/src/com/android/settings/WirelessSettings.java b/src/com/android/settings/WirelessSettings.java
index 60ae20d..6d1ce8d 100644
--- a/src/com/android/settings/WirelessSettings.java
+++ b/src/com/android/settings/WirelessSettings.java
@@ -16,28 +16,26 @@
 
 package com.android.settings;
 
-import android.app.admin.DevicePolicyManager;
-import android.bluetooth.BluetoothAdapter;
-import android.content.Context;
-import android.content.Intent;
-import android.net.ConnectivityManager;
-import android.net.wifi.WifiManager;
-import android.os.Bundle;
-import android.os.ServiceManager;
-import android.os.SystemProperties;
-import android.preference.CheckBoxPreference;
-import android.preference.Preference;
-import android.preference.PreferenceActivity;
-import android.preference.PreferenceScreen;
-import android.provider.Settings;
-import android.util.Log;
-
 import com.android.internal.telephony.TelephonyIntents;
 import com.android.internal.telephony.TelephonyProperties;
 import com.android.settings.bluetooth.BluetoothEnabler;
 import com.android.settings.wifi.WifiEnabler;
 
-public class WirelessSettings extends PreferenceActivity {
+import android.app.Activity;
+import android.app.admin.DevicePolicyManager;
+import android.bluetooth.BluetoothAdapter;
+import android.content.Context;
+import android.content.Intent;
+import android.net.ConnectivityManager;
+import android.os.Bundle;
+import android.os.ServiceManager;
+import android.os.SystemProperties;
+import android.preference.CheckBoxPreference;
+import android.preference.Preference;
+import android.preference.PreferenceScreen;
+import android.provider.Settings;
+
+public class WirelessSettings extends SettingsPreferenceFragment {
 
     private static final String KEY_TOGGLE_AIRPLANE = "toggle_airplane";
     private static final String KEY_TOGGLE_BLUETOOTH = "toggle_bluetooth";
@@ -71,7 +69,7 @@
             return true;
         }
         // Let the intents be launched by the Preference manager
-        return false;
+        return super.onPreferenceTreeClick(preferenceScreen, preference);
     }
 
     public static boolean isRadioAllowed(Context context, String type) {
@@ -85,21 +83,22 @@
     }
 
     @Override
-    protected void onCreate(Bundle savedInstanceState) {
+    public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
 
         addPreferencesFromResource(R.xml.wireless_settings);
 
+        final Activity activity = getActivity();
         CheckBoxPreference airplane = (CheckBoxPreference) findPreference(KEY_TOGGLE_AIRPLANE);
         CheckBoxPreference wifi = (CheckBoxPreference) findPreference(KEY_TOGGLE_WIFI);
         CheckBoxPreference bt = (CheckBoxPreference) findPreference(KEY_TOGGLE_BLUETOOTH);
 
-        mAirplaneModeEnabler = new AirplaneModeEnabler(this, airplane);
+        mAirplaneModeEnabler = new AirplaneModeEnabler(activity, airplane);
         mAirplaneModePreference = (CheckBoxPreference) findPreference(KEY_TOGGLE_AIRPLANE);
-        mWifiEnabler = new WifiEnabler(this, wifi);
-        mBtEnabler = new BluetoothEnabler(this, bt);
+        mWifiEnabler = new WifiEnabler(activity, wifi);
+        mBtEnabler = new BluetoothEnabler(activity, bt);
 
-        String toggleable = Settings.System.getString(getContentResolver(),
+        String toggleable = Settings.System.getString(activity.getContentResolver(),
                 Settings.System.AIRPLANE_MODE_TOGGLEABLE_RADIOS);
 
         // Manually set dependencies for Wifi when not toggleable.
@@ -122,12 +121,13 @@
 
         // Enable Proxy selector settings if allowed.
         Preference mGlobalProxy = findPreference(KEY_PROXY_SETTINGS);
-        DevicePolicyManager mDPM = (DevicePolicyManager)getSystemService(Context.DEVICE_POLICY_SERVICE);
+        DevicePolicyManager mDPM = (DevicePolicyManager)
+                activity.getSystemService(Context.DEVICE_POLICY_SERVICE);
         mGlobalProxy.setEnabled(mDPM.getGlobalProxyAdmin() == null);
 
         // Disable Tethering if it's not allowed
         ConnectivityManager cm =
-                (ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE);
+                (ConnectivityManager) activity.getSystemService(Context.CONNECTIVITY_SERVICE);
         if (!cm.isTetheringSupported()) {
             getPreferenceScreen().removePreference(findPreference(KEY_TETHER_SETTINGS));
         } else {
@@ -166,7 +166,7 @@
     }
 
     @Override
-    protected void onResume() {
+    public void onResume() {
         super.onResume();
 
         mAirplaneModeEnabler.resume();
@@ -175,7 +175,7 @@
     }
 
     @Override
-    protected void onPause() {
+    public void onPause() {
         super.onPause();
 
         mAirplaneModeEnabler.pause();
@@ -184,7 +184,7 @@
     }
 
     @Override
-    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
+    public void onActivityResult(int requestCode, int resultCode, Intent data) {
         if (requestCode == REQUEST_CODE_EXIT_ECM) {
             Boolean isChoiceYes = data.getBooleanExtra(EXIT_ECM_RESULT, false);
             // Set Airplane mode based on the return value and checkbox state