Android DiffUtil without moving items

Question

I am trying to update a RecyclerView based on a size (Int) passed to the adapter. I would like the adapter to add or remove items without moving any items as it appears to be now. I am sharing the code for DiffUtil below:

fun notifyChanges(newListSize: Int) {
        val diff = DiffUtil.calculateDiff(object : DiffUtil.Callback() {
            override fun areItemsTheSame(oldItemPosition: Int, newItemPosition: Int): Boolean {
                return true
            }
            override fun areContentsTheSame(oldItemPosition: Int, newItemPosition: Int): Boolean {
                return true
            }
            override fun getOldListSize() = columnNumber * rowNumber
            override fun getNewListSize() = newListSize
        })

        // Update number of tiles and dispatch changes
        tilesNumber = newListSize
        diff.dispatchUpdatesTo(this)
    }

I then call it as:

mAdapter.notifyChanges(columnNumber * rowNumber)

Any help will be appreciated.