Support two pane design in the Settings app.

1. Only enable this feature when the flag is on and library is supported
in this device.
2. Add a placeholder rule for home menu.
Network page will be shown to the right pane by default.
3. Add a rule for most sub settings pages.

Known issues:
1. Transition animation seems wrong in this cl.
2. App is closed if user taps back key on the second layer page in fold
state.

Test: Run the apk on large screen device and regular phone. No crash
happens
Bug: 197716926

Change-Id: I089717e84c5e92c6e5b02d9770a24376e250fea2
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index 64bef73..222931e 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -108,7 +108,9 @@
     <uses-permission android:name="android.permission.READ_DREAM_SUPPRESSION" />
     <uses-permission android:name="android.permission.MANAGE_APP_HIBERNATION" />
 
-    <application android:label="@string/settings_label"
+    <application
+            android:name=".SettingsApplication"
+            android:label="@string/settings_label"
             android:icon="@drawable/ic_launcher_settings"
             android:theme="@style/Theme.Settings"
             android:hardwareAccelerated="true"