Fixed a bug where the chronometer wasn't updating the time

When the countdown was set to true and the chronometer was set to
count down it wasn't updating the time, which is now fixed.

Change-Id: I4887d9eb09193c5636070edee9ba1bd13b9a23b5
Fixes: 28829131

core/java/android/widget/Chronometer.java

@@ -130,6 +130,7 @@ public class Chronometer extends TextView {
     @android.view.RemotableViewMethod
     public void setCountDown(boolean countDown) {
         mCountDown = countDown;
+        updateText(SystemClock.elapsedRealtime());
     }
 
     /**