docs: Fixed broken link in 'Displaying a Now Playing Card' lesson.
bug: 19555868

Change-Id: I0063c5a71e471b13dbe8e06054cbdc7dd8884b46
diff --git a/docs/html/training/tv/playback/now-playing.jd b/docs/html/training/tv/playback/now-playing.jd
index e158697..a4c321e 100644
--- a/docs/html/training/tv/playback/now-playing.jd
+++ b/docs/html/training/tv/playback/now-playing.jd
@@ -63,8 +63,8 @@
 
 <p>The Now Playing card shows up after {@link android.media.session.MediaSession#setActive(boolean) setActive(true)}
 is called, if the session is the highest priority session in the system. Also, note that your app
-must request the audio focus, as described in <a href="{@docRoot}training/managing-audio/audio-focus">
-Managing Audio Focus</a>.</p>
+must request the audio focus, as described in
+<a href="{@docRoot}training/managing-audio/audio-focus.html">Managing Audio Focus</a>.</p>
 
 <pre>
 private void handlePlayRequest() {