title: CardView background color states not being respected
body: <p>In brief:</p>
  
  <p>How can we define color states of CardView's cardBackgroundColor property (in a ListView layout, in this case)? </p>
  
  <p>(I am using RC1 of Android L developer preview, on a phone with 4.4 installed, and "com.android.support:cardview-v7:21.0.0-rc1" in build.gradle)</p>
  
  <p>Longer:</p>
  
  <p>In CardView layout, we set the corner radius and background color of the CardView via cardCornerRadius and cardBackgroundColor.</p>
  
  <p>However, the background color doesn't repect selected states, i.e. if the list item is pressed, for example.</p>
  
  <p>If, in the inner view of the CardView, you set a background colour, and associated states, which are respected, however, it will display over the corners you defined in the CardView.</p>
  
  <p>So, how can we ensure the states in CardView's cardBackgroundColor are respected?</p>
  
  <p>Here's the color used for the cardBackgroundColor, colour_with_states.xml:</p>
  
  <pre><code>&lt;selector xmlns:android="http://schemas.android.com/apk/res/android"&gt;
      &lt;item android:state_focused="true"  android:state_enabled="false" android:state_pressed="true" android:color="@android:color/holo_green_dark" /&gt;
      &lt;item android:state_focused="true"  android:state_enabled="false"                              android:color="@android:color/holo_green_dark" /&gt;
      &lt;item android:state_focused="true"                                android:state_pressed="true" android:color="@android:color/holo_green_dark" /&gt;
      &lt;item android:state_focused="false"                               android:state_pressed="true" android:color="@android:color/holo_green_dark" /&gt;
      &lt;item android:state_focused="true"                                                             android:color="@android:color/holo_green_dark" /&gt;
      &lt;!-- Only this below is seen in the cardview dispaly --&gt;
      &lt;item android:color="@android:color/holo_blue_bright" /&gt;
  &lt;/selector&gt;
  </code></pre>
  
  <p>And the layout that uses the CardView:</p>
  
  <pre><code>&lt;android.support.v7.widget.CardView
      xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:cardview="http://schemas.android.com/apk/res-auto"
      xmlns:tools="http://schemas.android.com/tools"
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      cardview:cardCornerRadius="10dp"
      cardview:cardBackgroundColor="@color/colour_with_states"
      &gt;
  
  &lt;!-- If we set a background color below, it will overwrite our radius defined above --&gt;
  &lt;TextView
      xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:tools="http://schemas.android.com/tools"
      tools:text="Lorem ipsum"
      android:id="@android:id/text1"
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      android:textAppearance="?android:attr/textAppearanceListItem"
      android:background="@null"
      android:gravity="center_vertical"
      android:paddingTop="8dip"
      android:paddingBottom="8dip"
      android:paddingStart="8dip"
      android:paddingEnd="8dip"
      /&gt;
  
  &lt;/android.support.v7.widget.CardView&gt;
  </code></pre>