title: Spinner does not apply dropDownSelector attribute
body: <p>I'm using spinner and want to add spinner - to change behavior depends of states(focused, pressed)</p>
  
  <p>sample project is here <a href="https://github.com/vovs/spinner_issue" rel="noreferrer">https://github.com/vovs/spinner_issue</a></p>
  
  <p>My code:</p>
  
  <p><strong>activity_main.xml</strong></p>
  
  <pre><code>&lt;Spinner
          android:id="@+id/spinner"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:layout_alignParentTop="true"
          android:layout_centerHorizontal="true"
          android:layout_marginTop="30dp"
          android:spinnerMode="dropdown"
          android:dropDownSelector="@drawable/spinner_state" /&gt;
  </code></pre>
  
  <p><strong>spinner_state.xml</strong></p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  
  &lt;selector xmlns:android="http://schemas.android.com/apk/res/android"&gt;
      &lt;item
          android:state_enabled="false"
          android:drawable="@color/black" /&gt;
      &lt;item
          android:state_pressed="true"
          android:state_enabled="true"
          android:drawable="@color/red" /&gt;
      &lt;item
          android:state_focused="true"
          android:state_enabled="true"
          android:drawable="@color/red" /&gt;
      &lt;item
          android:state_enabled="true"
          android:drawable="@color/gray" /&gt;
  &lt;/selector&gt;
  </code></pre>
  
  <p><strong>AndroidManifest:</strong></p>
  
  <pre><code>&lt;uses-sdk
          android:minSdkVersion="8"
          android:targetSdkVersion="16" /&gt;
  </code></pre>
  
  <p>So, if I run app in emulator Android 4.0.2 API 14 and try to select some item or scroll using wheel of my mouse no any effect, that I set in selector(when press or scrolling - items should be red, but it is blue - default for ICS color).</p>
  
  <p>For Android 2.2 API 8 when press or scroll using wheel(in this case state is focused) color is yellow[orange](default color for Android 2.2)</p>
  
  <p>How to enable selector for spinner?</p>
  
  <p><img src="https://i.stack.imgur.com/7ZGFW.png" alt="enter image description here"></p>