Remove obsolete TODO

- From b/399089118#comment2 "On external dispalys, RecentsViewContainer is always RecentsWindowManager, so onOverviewTargetChanged will never be called on external displays". So we we only need to track OverviewTargetChange for default display.

Fix: 399089118
Test: m
Flag: EXEMPT comment only change
Change-Id: Ica0527e45da6f0079bae5b69e9100b9f74d7f7ad

quickstep/src/com/android/quickstep/TouchInteractionService.java

@@ -908,8 +908,6 @@ public class TouchInteractionService extends Service {
 
     private void onOverviewTargetChanged(boolean isHomeAndOverviewSame) {
         mAllAppsActionManager.setHomeAndOverviewSame(isHomeAndOverviewSame);
-        // TODO (b/399089118): how will this work with per-display Taskbars? Is using the
-        //  default-display container ok?
         RecentsViewContainer newOverviewContainer =
                 mOverviewComponentObserver.getContainerInterface(
                         DEFAULT_DISPLAY).getCreatedContainer();