Modify Taskbar code to accommodate bubble bar gesture to stash/unstash

* Bubble bar typically follows the behavior of taskbar - if taskbar
  is shown, the bubble bar is shown, if taskbar hides, bubble bar
  hides.
* The bubble bar has 3 states: stashed, collapsed (unstashed but
  the bubbles are not expanded), and expanded. When bubbles are
  expanded, this means WMShell is rendering the bubble
  expanded view. In this situation taskbar becomes collapsed.

Bug: 253318833
Test: manual - flag turned on - see go/bubble-bar-tests
Test: manual - flag turned off:
             - launch an app, ensure taskbar is stashed
             - unstash taskbar, drag down on taskbar, ensure it
               becomes stashed
             - be in an app, unstash taskbar, interact with the app,
               ensure taskbar is stashed
             - be in an app, unstash taskbar, select an app from it,
               ensure taskbar is stashed & app is opened
Flag: WM_BUBBLE_BAR
Change-Id: I7b481d768182c8429160ab4a9b213b885a7d78bc

quickstep/src/com/android/launcher3/taskbar/TaskbarLauncherStateController.java

@@ -404,6 +404,14 @@ public class TaskbarLauncherStateController {
                     + ", mLauncherState: " + mLauncherState
                     + ", toAlignment: " + toAlignment);
         }
+        mControllers.bubbleControllers.ifPresent(controllers -> {
+            // Show the bubble bar when on launcher home or in overview.
+            boolean onHome = isInLauncher && mLauncherState == LauncherState.NORMAL;
+            boolean onOverview = mLauncherState == LauncherState.OVERVIEW;
+            controllers.bubbleStashController.setBubblesShowingOnHome(onHome);
+            controllers.bubbleStashController.setBubblesShowingOnOverview(onOverview);
+        });
+
         AnimatorSet animatorSet = new AnimatorSet();
 
         if (hasAnyFlag(changedFlags, FLAG_LAUNCHER_IN_STATE_TRANSITION)) {
@@ -474,7 +482,8 @@ public class TaskbarLauncherStateController {
                     public void onAnimationEnd(Animator animation) {
                         TaskbarStashController stashController =
                                 mControllers.taskbarStashController;
-                        stashController.updateAndAnimateTransientTaskbar(/* stash */ true);
+                        stashController.updateAndAnimateTransientTaskbar(
+                                /* stash */ true, /* bubblesShouldFollow */ true);
                     }
                 });
             } else {