Fix settings crash during pathological rotate.

Bug:14281882
Change-Id: If30a3e8eea35564853fc12c03f8ab63c258310c9
diff --git a/src/com/android/settings/notification/AppNotificationSettings.java b/src/com/android/settings/notification/AppNotificationSettings.java
index 172557d..c63ae63 100644
--- a/src/com/android/settings/notification/AppNotificationSettings.java
+++ b/src/com/android/settings/notification/AppNotificationSettings.java
@@ -114,6 +114,12 @@
     }
 
     @Override
+    public void onDestroyView() {
+        super.onDestroyView();
+        mListViewState = null;  // you're dead to me
+    }
+
+    @Override
     public void onResume() {
         super.onResume();
         loadAppsList();