Fix missing recents screenshots

We were using the "visible layer list" when taking screenshots,
which doesn't work when a layer is behind other opaque layers
and therefore hidden.

We fix this by using the full layer list, filtered by the
layerstack of the display we're looking at.

Bug: 7552304
Change-Id: I4b6f77e5511aea94f8d218975b6e22738e7e5d5b