Fix HighlightingFragment

- get themed highlight drawable

Similar fix as I945eca98e1d73fda3b290a6ababfd1fb41118d8f

Change-Id: Ieabee16433ec29044a7a26875c3325231a287c88
diff --git a/src/com/android/settings/HighlightingFragment.java b/src/com/android/settings/HighlightingFragment.java
index 3595eec..7e4ebf2 100644
--- a/src/com/android/settings/HighlightingFragment.java
+++ b/src/com/android/settings/HighlightingFragment.java
@@ -67,7 +67,7 @@
     }
 
     private Drawable getHighlightDrawable() {
-        return getResources().getDrawable(R.drawable.preference_highlight);
+        return getActivity().getDrawable(R.drawable.preference_highlight);
     }
 
     private void highlightView(String key) {