title: SwitchPreferenceCompat: android:switchTextOff / switchTextOn doesn't work
body: <p>I'm trying to display a switchPreference which allows the user to display the distance according to miles or kms. I'm using the SwitchPreferenceCompat support library. According to the library, I can use the textSwitchOff and textSwitchOn to add text to the switch. I just want to add "km" or "miles" to my switch so that the user knows which metric is displayed.</p>
  
  <p>According to <a href="http://developer.android.com/reference/android/support/v7/preference/SwitchPreferenceCompat.html#attr_android:switchTextOff" rel="noreferrer">this doc</a>, all I need is the code below:</p>
  
  <pre><code>&lt;android.support.v7.preference.PreferenceCategory
      android:layout="@layout/preferences_category"
      android:title="Distance" &gt;
  
      &lt;android.support.v7.preference.SwitchPreferenceCompat android:title="KM or Miles"
          android:key="kmormiles"
          android:switchTextOff="miles"
          android:switchTextOn="km"
          android:defaultValue="true"/&gt;
  
  &lt;/android.support.v7.preference.PreferenceCategory&gt;
  </code></pre>
  
  <p>However, the switch just looks like a normal switch, there is no extra text on the switch itself.</p>
  
  <p><a href="https://i.stack.imgur.com/4m8eW.png" rel="noreferrer"><img src="https://i.stack.imgur.com/4m8eW.png" alt="enter image description here"></a></p>
  
  <p>How do I get it to display with the textOn and textOff?</p>
  
  <p>I also tried the following:</p>
  
  <pre><code>    addPreferencesFromResource(R.xml.preferences);
      kmormiles = (SwitchPreferenceCompat) findPreference("kmormiles");
      kmormiles.setSwitchTextOff("Km");
      kmormiles.setSwitchTextOn("miles");
  </code></pre>
  
  <p>Still doesn't work. I'm trying it on two different genymotion emulators, API 16 and API 21.</p>