title: Using logical NOT with android:dependency from preferences
body: <p><a href="http://developer.android.com/reference/android/preference/Preference.html#attr_android:dependency">http://developer.android.com/reference/android/preference/Preference.html#attr_android:dependency</a></p>
  
  <p>if I want my list to be dependent from other check preference named on_off I can do this</p>
  
  <pre><code>&lt;ListPreference
      android:defaultValue="100"
      android:dependency="on_off"
      android:dialogTitle="text"
      android:entries="@array/display_values"
      android:entryValues="@array/entry_values"
      android:key="preferences_text"
      android:summary="text"
      android:title="text" /&gt;
  </code></pre>
  
  <p>and every time when the check preference on_off have value false this list preference will be disabled.</p>
  
  <p>But what If I want everytime when on_off is true the list preference to be disabled ?
  I need something like logical NOT for the android:dependency </p>
  
  <p>is this possible ?</p>