Kibana integration doesn't support new 8.0 logging format

[adriansr]

Starting with v8.0, Kibana introduces a new logging system that changes the JSON fields that are generated.

The kibana module doesn't support the new fields: expects a pid field, while the new format outputs ECS-compatible process.pid. Other fields need review.

This results in an ingestion:

"error.message": "field [kibana.log.meta.pid] doesn't exist"

(Same issue as elastic/beats#31216)

[elasticmachine]

Pinging @elastic/integrations (Team:Integrations)

[botelastic]

Hi! We just realized that we haven't looked into this issue in a while. We're sorry! We're labeling this issue as Stale to make it hit our filters and make sure we get back to it as soon as possible. In the meantime, it'd be extremely helpful if you could take a look at it as well and confirm its relevance. A simple comment with a nice emoji will be enough :+1. Thank you for your contribution!