title: Should the index passed to notifyItemChanged consider placeholder items?
body: <p><code>PagingDataAdapter</code> from Paging3 library internally manages two semantically different lists. <code>adapter.snapshot()</code> returns a <code>ItemSnapshotList</code> which includes placeholder elements. <code>adapter.snapshot().items</code> return a <code>List</code> which excludes placeholder items.</p>
  <p>Now I had to update an element using it's id. Should find and pass the index based on <code>ItemSnapshotList</code> or <code>List</code>? Eg:</p>
  <pre><code>adapter.notifyItemChanged(
      adapter.snapshot().indexOfFirst { it!!.id == id } // is this correct ?
      adapter.snapshot().items.indexOfFirst { it.id == id } // or is this ?
      , PAYLOAD_STATUS to Status.Active  // payloads
  )
  </code></pre>