title: Checkbox error don't disappears after checking
body: <p>In my form, I hava a CeckBox and its required to be checked to submit. If it's unchecked, I call setError() to warn the user. But, once the error is displayed, it don't disappears, no matter the checkbox is checked or not.
  Other bug is that if the error text is much long, it appears incomplete. In landscape mode, it appears complete.</p>
  
  <p>checkbox xml:</p>
  
  <pre><code>&lt;CheckBox 
          android:id="@+id/reg_terms"
          android:layout_width="fill_parent"
          android:layout_height="wrap_content"
          android:text="Li e concordo com os Termos de Uso."
          android:focusableInTouchMode="true"
          android:focusable="true"
          android:textColor="#000000"
          android:checked="false"
          /&gt;
  </code></pre>
  
  <p>Validation (inside submitButtons's onClick):</p>
  
  <pre><code>if(!reg_terms.isChecked()){
    reg_terms.setError("É preciso aceitar os Termos de Uso");
    validation = false;
    }
  </code></pre>
  
  <p>There isn't any "addOnFocusChangedListener" methot I could use to "dismiss" the error if user checks the box? And how could I avoid the error text to appears incomplete?</p>
  
  <p>Viele danke für alle Hilfe. :D</p>