Don't toggle scrollbar during predicitve back swipe to avoid flicker

Fix: 329437430
Test: manual - attach video to bug
Flag: aconfig com.android.launcher3.enable_predictive_back_gesture TEAMFOOD
Change-Id: I8c959fbb02948011be59a17752a140b1a07ca6b9

src/com/android/launcher3/allapps/AllAppsTransitionController.java

@@ -295,9 +295,6 @@ public class AllAppsTransitionController
         mLauncher.getScrimView().setScrimHeaderScale(scaleProgress);
 
         AllAppsRecyclerView rv = mLauncher.getAppsView().getActiveRecyclerView();
-        if (rv != null && rv.getScrollbar() != null) {
-            rv.getScrollbar().setVisibility(scaleProgress < 1f ? View.INVISIBLE : View.VISIBLE);
-        }
 
         // Disable view clipping from all apps' RecyclerView up to all apps view during scale
         // animation, and vice versa. The goal is to display extra roll(s) app icons (rendered in