Fix window leak and receiver leak. Bug: 2520143 and Bug: 2517390

In Activity.onDestroy close any open SearchDialog to avoid a window leak.

Register/unregister broadcast receiver in onStart/onStop of the dialog.
diff --git a/core/java/android/app/Activity.java b/core/java/android/app/Activity.java
index 3c5a1c7..a962391 100644
--- a/core/java/android/app/Activity.java
+++ b/core/java/android/app/Activity.java
@@ -1320,6 +1320,11 @@
             }
             mManagedCursors.clear();
         }
+
+        // Close any open search dialog
+        if (mSearchManager != null) {
+            mSearchManager.stopSearch();
+        }
     }
 
     /**