Revert "Fix shelf being visible on kiosk next home screen"

This reverts commit 71bbd6d8.

Reason for revert: Kiosk Next not needed any more

Original change's description:
> Fix shelf being visible on kiosk next home screen
> 
> Shelf should not be visible on Kiosk Next home screen. Starting drag
> gesture during transition to home screen can cause shelf remaining stuck
> and visible. To prevent that cancel drag gesture when home screen
> animation is finished.
> 
> Bug: 968635
> Change-Id: I89cfaebbfc9eed0e8ef916b382fdb88f470399f0
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1638917
> Commit-Queue: Aga Wronska <agawronska@chromium.org>
> Reviewed-by: Michael Giuffrida <michaelpg@chromium.org>
> Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#665561}

TBR=xiyuan@chromium.org,michaelpg@chromium.org,agawronska@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 968635
Change-Id: I9b6ebf663ffbc76e2fd39a2aa185833908516528
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1698531Reviewed-by: Aga Wronska <agawronska@chromium.org>
Commit-Queue: Aga Wronska <agawronska@chromium.org>
Cr-Commit-Position: refs/heads/master@{#676876}

ash/shelf/shelf_layout_manager.cc

@@ -702,16 +702,6 @@ void ShelfLayoutManager::OnHomeLauncherAnimationComplete(bool shown,
   is_home_launcher_shown_ = shown;
   is_home_launcher_target_position_shown_ = false;
   MaybeUpdateShelfBackground(AnimationChangeType::IMMEDIATE);
-
-  // Cancel ongoing drag when self is hidden on home screen to prevent
-  // visibility issues.
-  if (shown && drag_status_ != kDragNone &&
-      !Shell::Get()
-           ->home_screen_controller()
-           ->delegate()
-           ->ShouldShowShelfOnHomeScreen()) {
-    CancelDrag();
-  }
 }
 
 void ShelfLayoutManager::OnWindowActivated(ActivationReason reason,