Prevent ANR in Home when changing orientation.
Bug #2504556

This solves the issue by keeping the GL context, the RS context and
the RS scene around, across orientation changes.

Change-Id: I8e3dc6e6bf039087046d49d2826c8800c5bef582
diff --git a/src/com/android/launcher2/Launcher.java b/src/com/android/launcher2/Launcher.java
index df2dd66..f7cb749 100644
--- a/src/com/android/launcher2/Launcher.java
+++ b/src/com/android/launcher2/Launcher.java
@@ -424,11 +424,12 @@
     public Object onRetainNonConfigurationInstance() {
         // Flag the loader to stop early before switching
         mModel.stopLoader();
+        mAllAppsGrid.surrender();
 
         if (PROFILE_ROTATE) {
             android.os.Debug.startMethodTracing("/sdcard/launcher-rotate");
         }
-        return null;
+        return Boolean.TRUE;
     }
 
     // We can't hide the IME if it was forced open.  So don't bother