open fun setItemSpacingPx(@Px spacingPx: Int): Unit
Set a pixel value to use as spacing between items. If this is a positive number an item decoration will be added to space all items this far apart from each other. If the value is 0 or negative no extra spacing will be used, and any previous spacing will be removed.
This only works if a LinearLayoutManager or GridLayoutManager is used with this RecyclerView.
This can also be set via the app:itemSpacing styleable attribute.