Add WifiPickerActivity for PICK_WIFI_NETWORK

- We disable left pane when PICK_WIFI_NETWORK intent is used.
- Add ButtonBarHandler interface and let SettingsPreferenceFragment
  use it instead of Settings. Note that
  PreferenceActivity#hasNextButton() and
  PreferenceActivity#getNextButton() are currently protected methods,
  while Settings' relevants are public.

Bug: 3355247
Change-Id: Ie0fae8a1dbce9c7ce37375dff8395dc09b1cc74e
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index bc58a7e..0f2390c 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -110,7 +110,6 @@
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
                 <action android:name="android.settings.WIFI_SETTINGS" />
-                <action android:name="android.net.wifi.PICK_WIFI_NETWORK" />
                 <category android:name="android.intent.category.DEFAULT" />
                 <category android:name="android.intent.category.VOICE_LAUNCH" />
                 <category android:name="com.android.settings.SHORTCUT" />
@@ -125,6 +124,16 @@
                 android:value="com.android.settings.Settings$WirelessSettingsActivity" />
         </activity>
 
+        <activity android:name=".wifi.WifiPickerActivity"
+                  android:theme="@android:style/Theme.Holo"
+                  android:clearTaskOnLaunch="true">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+                <action android:name="android.net.wifi.PICK_WIFI_NETWORK" />
+                <category android:name="android.intent.category.DEFAULT" />
+            </intent-filter>
+        </activity>
+
         <activity android:name=".wifi.WifiSettingsForSetupWizardXL"
                   android:theme="@android:style/Theme.Holo.NoActionBar"
                   android:clearTaskOnLaunch="true"