Bugfix: activity type preference has to update the icon when user change the activity type. Fixes #985.

src/main/java/de/dennisguse/opentracks/settings/ActivityTypePreference.java

@@ -116,6 +116,7 @@ public class ActivityTypePreference extends DialogPreference {
         }
 
         public void updateUI(String iconValue) {
+            updateIcon(iconValue);
             textView.setText(getActivity().getString(TrackIconUtils.getIconActivityType(iconValue)));
             textView.clearFocus();
         }