Resurrect the All Apps button.

Change-Id: Ic7dc985bfc1eec6d6c059ff37a61c84b8cb103de
diff --git a/proguard.flags b/proguard.flags
index b8aeff7..fb145aa 100644
--- a/proguard.flags
+++ b/proguard.flags
@@ -2,3 +2,5 @@
   public void previousScreen(android.view.View);
   public void nextScreen(android.view.View);
 }
+
+-keep class com.android.launcher2.AllApps3D.Defines