Fix a minor issue of "restore default" should also improve
performance as well.

Change-Id: I1a762ed78dc27bb711b652431481925c9bd1b8b5
diff --git a/src/com/android/camera/PreferenceGroup.java b/src/com/android/camera/PreferenceGroup.java
index d4972f8..720e8a2 100644
--- a/src/com/android/camera/PreferenceGroup.java
+++ b/src/com/android/camera/PreferenceGroup.java
@@ -49,6 +49,13 @@
         return list.size();
     }
 
+    @Override
+    public void reloadValue() {
+        for (CameraPreference pref : list) {
+            pref.reloadValue();
+        }
+    }
+
     /**
      * Finds the preference with the given key recursively. Returns
      * <code>null</code> if cannot find.