Updating the Static Wallpaper picker for Tablet

- Updated WallpaperChooser to use FragmentDialogs
- Backwards compatible with old WallpaperChooser
  UI on non XLarge screens
- There is a known bug with AlertDialogs (b/3225529)
  that prevents an AlertDialog to expand to fit its
  content. The squishing of the GridView is caused
  by that bug.

Change-Id: I49381aab4aa24362e8c92da284797fce0e63823c
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index 4aa5d68..905b8b6 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -88,6 +88,7 @@
             android:name="com.android.launcher2.WallpaperChooser"
             android:label="@string/pick_wallpaper"
             android:icon="@drawable/ic_launcher_wallpaper"
+            android:theme="@style/Theme.WallpaperPicker"
             android:screenOrientation="nosensor"
             android:finishOnCloseSystemDialogs="true">
             <intent-filter>