title: TextView setText doesn't work on custome layout in PreferenceFragment
body: <p>I'm using <code>PreferenceFragment</code> with some default preferences categories and one custom layout:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android" &gt;
  
      &lt;PreferenceCategory
          android:key="first_category"
          android:title="config" &gt;
          &lt;EditTextPreference
              android:defaultValue="example"
              android:dialogMessage="text"
              android:dialogTitle="Title"
              android:key="mykey"
              android:summary="summary"
              android:title="title" /&gt;
  
          &lt;Preference
              android:key="test_connection"
              android:title="Test connection"
              android:layout="@layout/test_conn"  /&gt;
   &lt;/PreferenceCategory&gt;
  
  &lt;/PreferenceScreen&gt;
  </code></pre>
  
  <p>My test_conn layout:</p>
  
  <pre><code>   &lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_marginBottom="6dip"
      android:layout_marginLeft="15dip"
      android:layout_marginRight="6dip"
      android:layout_marginTop="6dip"
      android:layout_weight="1" &gt;
  
      &lt;TextView
          android:id="@+id/title"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:layout_alignParentLeft="true"
          android:layout_marginLeft="20dp"
          android:ellipsize="marquee"
          android:fadingEdge="horizontal"
          android:text="Test connection"
          android:textAppearance="?android:attr/textAppearanceLarge" /&gt;
  
      &lt;TextView
          android:id="@+id/summary"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:layout_alignParentRight="true"
          android:layout_marginRight="20dp"
          android:ellipsize="marquee"
          android:fadingEdge="horizontal"
          android:text="Ko"
          android:textAppearance="?android:attr/textAppearanceLarge"
          android:textColor="#ff0000"
          android:textStyle="bold" /&gt;
  
  &lt;/RelativeLayout&gt;
  </code></pre>
  
  <p>I'm reading the textview <code>R.id.summary</code> with this code:</p>
  
  <pre><code>        addPreferencesFromResource(R.xml.preferences);
          findPreference(TEST_CONN).setOnPreferenceClickListener(this);    
          Preference custom = findPreference(TEST_CONN);
          customv = custom.getView(null, null);
          res = (TextView) customv.findViewById(R.id.summary);
  </code></pre>
  
  <p>I can read correctly my TextView, but if I try to change the text, for example inside an asynctask, I can't see the text changed.</p>
  
  <p>This is a part of asynctask:</p>
  
  <pre><code>        @Override
      protected void onPostExecute(Boolean result) {
          if (result == true){
              res.setText("Ok");
              res.setTextColor(Color.GREEN);
          }
          else {
              res.setText("Ko");
              res.setTextColor(Color.RED);
          }
          pdia.dismiss();
      }
  </code></pre>
  
  <p>When the user click on the preference "test_connection", an asynctask starts and in the funzion onPostExecute I modify the text, but doesn't work. Am I missing something? Should I read the textview with another method? </p>