Add non-transparent background to dashboard items.

Bug: 30297664
Change-Id: Ia6173e8b0d5852a1c454ae466886f894c72e3e5f

res/drawable/selectable_card.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+     Copyright (C) 2016 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.
+-->
+
+<ripple
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:color="?android:attr/colorControlHighlight">
+    <item android:drawable="@color/card_background"/>
+</ripple>

res/layout/support_tile.xml

@@ -19,7 +19,7 @@
     xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
     android:layout_height="wrap_content"
-    android:background="?android:attr/selectableItemBackground"
+    android:background="@drawable/selectable_card"
     android:gravity="center_vertical"
     android:minHeight="@dimen/support_tile_min_height"
     android:orientation="horizontal">