title: Button style working in Android 5 but not Android 4
body: <p>I have a button style with a blue background that works fine in API 22, but the same button appears in dark grey without the applied style in Android 4. This is my style: </p>
  
  <pre><code>&lt;style name="MyApp.Plain" parent="Theme.AppCompat.NoActionBar"&gt;
        &lt;item name="android:windowBackground"&gt;@drawable/background&lt;/item&gt;
        &lt;item name="android:buttonStyle"&gt;@style/MyApp.Widget.Button&lt;/item&gt;
  &lt;/style&gt;
  
  
    &lt;style name="MyApp.Widget.Button" parent="@android:style/Widget.Button"&gt;
        &lt;item name="android:background"&gt;@drawable/btn_blue&lt;/item&gt;
        &lt;item name="android:focusable"&gt;true&lt;/item&gt;
        &lt;item name="android:clickable"&gt;true&lt;/item&gt;
        &lt;item name="android:textStyle"&gt;bold&lt;/item&gt;
        &lt;item name="android:textSize"&gt;14sp&lt;/item&gt;
        &lt;item name="android:textColor"&gt;#fff&lt;/item&gt;
        &lt;item name="android:gravity"&gt;center_vertical|center_horizontal&lt;/item&gt;
     &lt;/style&gt;
  </code></pre>
  
  <p>My btn_blue.xml</p>
  
  <pre><code>&lt;selector xmlns:android="http://schemas.android.com/apk/res/android"&gt;
  
      &lt;item android:drawable="@drawable/btn_disabled" android:state_enabled="false"/&gt;
      &lt;item android:drawable="@drawable/btn_pressed" android:state_enabled="true" android:state_pressed="true"/&gt;
      &lt;item android:drawable="@drawable/btn_normal_blue" android:state_enabled="true"/&gt;
  
  &lt;/selector&gt;
  </code></pre>
  
  <p>and btn_normal_blue.xml</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;shape xmlns:android="http://schemas.android.com/apk/res/android"
      android:shape="rectangle" &gt;
  
      &lt;gradient
          android:angle="90"
          android:endColor="#368ac6"
          android:startColor="#0e58a4" /&gt;
  
      &lt;corners android:radius="20dp" /&gt;
  
  &lt;/shape&gt;
  </code></pre>
  
  <p>What could be the reason for this behavior and how can I fix this? </p>
  
  <p>EDIT: This does not work with support v7:22.2.0, but does work with v7:21.0.3. I didn't change anything besides the dependency and changed AppCompatActivity to ActionBarActivity. </p>
  
  <p>Possibly this is an Android bug. </p>