Simplifying some scrollbar binding logic in all-apps

Bug: 256684299
Test: Manual
Change-Id: I1cee6cb783f0f805d9a0f0a4b2b668a709cacf1a

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

@@ -43,7 +43,6 @@ import com.android.launcher3.R;
 import com.android.launcher3.Utilities;
 import com.android.launcher3.logging.StatsLogManager;
 import com.android.launcher3.views.ActivityContext;
-import com.android.launcher3.views.RecyclerViewFastScroller;
 
 import java.util.List;
 
@@ -274,10 +273,6 @@ public class AllAppsRecyclerView extends FastScrollRecyclerView {
                 : getRootWindowInsets().getSystemWindowInsetBottom();
     }
 
-    public RecyclerViewFastScroller getScrollbar() {
-        return mScrollbar;
-    }
-
     @Override
     public boolean hasOverlappingRendering() {
         return false;