[Maps][File upload] GeoJSON import taking much longer (or crashing) when adding indexed source

[kindsun]

A recent change appears to be delaying addition of indexed layers, or even making adding some datasets that could previously be added now impossible. Even smaller datasets now appear to take a while to add as indicated by the process spinner on the Layers TOC. The issue appears to occur sometime after indexing but before adding the layer to the map.

Frequently the files are in fact indexed and can be added without any issue if you cancel adding the imported layer and instead back out and add a Document source layer using the same indexed data.

cc @alexfrancoeur

[elasticmachine]

Pinging @elastic/kibana-gis

[kindsun]

I think the behavior I'm seeing was introduced after #40102 was identified, but will close if it ends up being a dupe.

[kindsun]

To reproduce this issue, here a couple of files which demonstrate the behavior. Depending on machine resources, these files will either A. crash the browser tab or B. take > 5 seconds (sometimes much longer) during the final add step when indexed data is added to the map

test files.tar.gz