Revert "Completely destroy Launcher's Taskbar."

Revert submission 28102205

Reason for revert: Potential test breakage.

Reverted changes: ag/28102205

Change-Id: If7fa1ff192a240e753e5c245d591d46e594e5a6f
Flag: TEST_ONLY
Bug: 230027385
Test: Presubmit
diff --git a/quickstep/src/com/android/launcher3/taskbar/TaskbarManager.java b/quickstep/src/com/android/launcher3/taskbar/TaskbarManager.java
index 8786cd6..5d6591b 100644
--- a/quickstep/src/com/android/launcher3/taskbar/TaskbarManager.java
+++ b/quickstep/src/com/android/launcher3/taskbar/TaskbarManager.java
@@ -610,7 +610,8 @@
         }
     }
 
-    private void addTaskbarRootViewToWindow() {
+    @VisibleForTesting
+    public void addTaskbarRootViewToWindow() {
         if (enableTaskbarNoRecreate() && !mAddedWindow && mTaskbarActivityContext != null) {
             mWindowManager.addView(mTaskbarRootLayout,
                     mTaskbarActivityContext.getWindowLayoutParams());
@@ -618,7 +619,8 @@
         }
     }
 
-    private void removeTaskbarRootViewFromWindow() {
+    @VisibleForTesting
+    public void removeTaskbarRootViewFromWindow() {
         if (enableTaskbarNoRecreate() && mAddedWindow) {
             mWindowManager.removeViewImmediate(mTaskbarRootLayout);
             mAddedWindow = false;
diff --git a/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/rules/TaskbarUnitTestRule.kt b/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/rules/TaskbarUnitTestRule.kt
index 74c2390..12f946e 100644
--- a/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/rules/TaskbarUnitTestRule.kt
+++ b/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/rules/TaskbarUnitTestRule.kt
@@ -119,14 +119,18 @@
                 try {
                     // Replace Launcher Taskbar window with test instance.
                     instrumentation.runOnMainSync {
-                        launcherTaskbarManager?.destroy()
+                        launcherTaskbarManager?.removeTaskbarRootViewFromWindow()
                         taskbarManager.onUserUnlocked() // Required to complete initialization.
                     }
 
                     injectControllers()
                     base.evaluate()
                 } finally {
-                    instrumentation.runOnMainSync { taskbarManager.destroy() }
+                    // Revert Taskbar window.
+                    instrumentation.runOnMainSync {
+                        taskbarManager.destroy()
+                        launcherTaskbarManager?.addTaskbarRootViewToWindow()
+                    }
                 }
             }
         }