Added example of customizing setup wallpaper

Bug: 17973320
Change-Id: I9dda51ba525a0f28d8db30878b06171b793aaa6a
diff --git a/apps/SetupCustomizer/res/values/strings.xml b/apps/SetupCustomizer/res/values/strings.xml
index 7572d9f..f53fb11 100644
--- a/apps/SetupCustomizer/res/values/strings.xml
+++ b/apps/SetupCustomizer/res/values/strings.xml
@@ -2,7 +2,10 @@
 
     <string name="app_label">SetupCustomizer</string>
 
-    <!-- Welcome messgae -->
+    <!-- Welcome message -->
     <string name="welcome_message">welcome_message</string>
 
+    <!-- Custom wallpaper [DO NOT TRANSLATE] -->
+    <string name="setup_wallpaper_component" translatable="false">com.android.systemui/com.android.systemui.ImageWallpaper</string>
+
 </resources>