Update visual style shortcut picker and make it async

* Use dialog when in XL screen size
* Show different strings in launcher and in dialog/activity title
* Add cancel button to picker
* Move accounts query to AsyncTask
* Remove obsolete AccountsAdapter

Bug: 3093928
Change-Id: Ief771482c6db684c434c21cf92844c37a927d34a
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index 97ac3d7..4a99cb8 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -147,10 +147,13 @@
 
         <activity
             android:name=".activity.AccountShortcutPicker"
-            android:label="@string/app_name"
+            android:label="@string/account_shortcut_picker_title"
             android:enabled="false"
+            android:theme="@android:style/Theme.Holo.DialogWhenLarge"
             >
-            <intent-filter>
+            <intent-filter
+                android:label="@string/account_shortcut_picker_name"
+                >
                 <action android:name="android.intent.action.CREATE_SHORTCUT" />
                 <category android:name="android.intent.category.DEFAULT" />
             </intent-filter>