title: EditTextPreference - only numeric value inputType - isn't working
body: <pre><code>&lt;android.support.v7.preference.EditTextPreference
              android:key="prefTest"
              android:title="test number input"
              android:inputType="numberDecimal|numberSigned"
              android:defaultValue="800"/&gt;
  </code></pre>
  
  <p>It still shows regular keyboard and allows me to type any character</p>
  
  <p>Is there something wrong with <code>android.support.v7</code>?</p>