When RecyclerView's LayoutManager is horizontal LinearLayoutManager, ItemDragHelperCallback does not work correctly

[ZhanXuzhao]

Problem describe:
When RecyclerView's LayoutManager is horizontal LinearLayoutManager, viewHolder can not be dragged left or right.

Problem code:
ItemDragHelperCallback getMovementFlags()

        if (manager instanceof GridLayoutManager || manager instanceof StaggeredGridLayoutManager) {
            dragFlags = ItemTouchHelper.UP | ItemTouchHelper.DOWN | ItemTouchHelper.LEFT | ItemTouchHelper.RIGHT;
        } else {
            dragFlags = ItemTouchHelper.UP | ItemTouchHelper.DOWN;
        }

Fix:

        if (manager instanceof GridLayoutManager || manager instanceof StaggeredGridLayoutManager) {
            dragFlags = ItemTouchHelper.UP | ItemTouchHelper.DOWN | ItemTouchHelper.LEFT | ItemTouchHelper.RIGHT;
        } else { // LinearLayoutManager
            LinearLayoutManager linearLayoutManager = (LinearLayoutManager) manager;
            if (linearLayoutManager.getOrientation() == LinearLayoutManager.HORIZONTAL) {
                dragFlags = ItemTouchHelper.LEFT | ItemTouchHelper.RIGHT;
            } else {
                dragFlags = ItemTouchHelper.UP | ItemTouchHelper.DOWN;
            }
        }