Improve Preference highlight effect

- restrict the effect to the Preference View itself

Change-Id: I3ab04433e1acecb906d0a458b31314f97b9bda03

res/drawable/preference_highlight.xml

@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2014 The Android Open Source Project
+
+     Licensed under the Apache License, Version 2.0 (the "License");
+     you may not use this file except in compliance with the License.
+     You may obtain a copy of the License at
+
+          http://www.apache.org/licenses/LICENSE-2.0
+
+     Unless required by applicable law or agreed to in writing, software
+     distributed under the License is distributed on an "AS IS" BASIS,
+     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+     See the License for the specific language governing permissions and
+     limitations under the License.
+-->
+
+<touch-feedback xmlns:android="http://schemas.android.com/apk/res/android"
+                android:tint="?android:attr/colorButtonPressed"
+                android:pinned="true">
+    <item android:id="@android:id/mask"
+          android:drawable="@android:color/white" />
+</touch-feedback>
+