Exit from quick scrub if unable to launch task onQuickScrubEnd

Bug: 76152304
Change-Id: I142b1a894d4f1e2dcf18631e0599482ff4845995
diff --git a/quickstep/src/com/android/quickstep/QuickScrubController.java b/quickstep/src/com/android/quickstep/QuickScrubController.java
index d263fbf..986eb48 100644
--- a/quickstep/src/com/android/quickstep/QuickScrubController.java
+++ b/quickstep/src/com/android/quickstep/QuickScrubController.java
@@ -87,6 +87,9 @@
             TaskView taskView = ((TaskView) mRecentsView.getPageAt(page));
             if (taskView != null) {
                 taskView.launchTask(true);
+            } else {
+                // Break out of quick scrub so user can interact with launcher.
+                mActivity.onBackPressed();
             }
         };
         int snapDuration = Math.abs(page - mRecentsView.getPageNearestToCenterOfScreen())