Have responsive taskbar UI during swipe up gesture.

- Makes taskbar threshold an absolute Y threshold
  instead of a distance threshold.
- Moves handle, taskbar view, and taskbar background
  during the swipe up gesture

Next CL will address transforming the nav handle <-> taskbar
and ensuring that there's a clean handoff

Bug: 246631059
Test: swipe up on taskbar, release. see bounce
      swipe up on taskbar to go home, proper icon alignment
      swipe up on taskbar, pause for overview, see bounce
      -> further movement should not move taskbar
      test launcher3

Change-Id: I141236fd72428cda7edd0ff116de1d478d18c722

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

@@ -91,6 +91,7 @@ public class TaskbarViewController implements TaskbarControllers.LoggableTaskbar
             this::updateTranslationY);
     private AnimatedFloat mTaskbarNavButtonTranslationY;
     private AnimatedFloat mTaskbarNavButtonTranslationYForInAppDisplay;
+    private float mTaskbarIconTranslationYForSwipe;
 
     private final int mTaskbarBottomMargin;
 
@@ -260,9 +261,18 @@ public class TaskbarViewController implements TaskbarControllers.LoggableTaskbar
         mTaskbarView.setScaleY(scale);
     }
 
+    /**
+     * Sets the translation of the TaskbarView during the swipe up gesture.
+     */
+    public void setTranslationYForSwipe(float transY) {
+        mTaskbarIconTranslationYForSwipe = transY;
+        updateTranslationY();
+    }
+
     private void updateTranslationY() {
         mTaskbarView.setTranslationY(mTaskbarIconTranslationYForHome.value
-                + mTaskbarIconTranslationYForStash.value);
+                + mTaskbarIconTranslationYForStash.value
+                + mTaskbarIconTranslationYForSwipe);
     }
 
     private void updateIconsBackground() {