title: Show an only one dialog to write/set two EditTextPreferences
body: <p>I'm creating a setting activity with an username and password. I use two editTextPreferences, they display their dialog independently one of the other. 
  What I want is to have an only one dialog where I can write the username and the password in different editText but in the same dialog using preferences. Is it possible?</p>
  
  <p>THis is my current code:</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:title="@string/settings_server"&gt;
  
      &lt;EditTextPreference
          android:key="@string/user_"
          android:title="@string/settings_user"/&gt;
  
      &lt;EditTextPreference
          android:inputType="textPassword"
          android:key="@string/password_"
          android:title="@string/settings_password"/&gt;
  
  
  
     &lt;/PreferenceCategory&gt;
  
  
  &lt;/PreferenceScreen&gt;
  </code></pre>