Show drag handle indictor in 2 zone model

Note this is just the tiny arrow we show in accessibility mode, will
probably need to get some updated visual treatment going forward.

Bug: 143361609
Change-Id: I65975727f101984429aadc35a650826e36d9c9aa

quickstep/src/com/android/quickstep/views/ShelfScrimView.java

@@ -237,6 +237,13 @@ public class ShelfScrimView extends ScrimView<BaseQuickstepLauncher>
         }
     }
 
+    @Override
+    protected boolean shouldDragHandleBeVisible() {
+        boolean twoZoneSwipeModel = FeatureFlags.ENABLE_OVERVIEW_ACTIONS.get()
+                && SysUINavigationMode.removeShelfFromOverview(mLauncher);
+        return twoZoneSwipeModel || super.shouldDragHandleBeVisible();
+    }
+
     @Override
     protected void onDraw(Canvas canvas) {
         drawBackground(canvas);