[Lens] fields with data don't appear on the field list

[AlonaNadler]

Lens is hiding fields in the field list that have data in them. Only show fields with data switch is on but still several of fields which has data in them are hidden

[wylieconlon]

Already fixed by #55625

[wylieconlon]

I was wrong, this is a different issue, happening in 7.5.1. It seems like the field you're looking at is only present in small percentage of documents, and since we only look at 500 documents to do the sampling, this could be missed.

The closest related issue is this one, where if you had any filters applied, this would be more obvious: #52826