Add IT for final_pipeline support with streaming messages in Pull Based Ingestion #20879
Description
Is your feature request related to a problem? Please describe
Add IT
Describe the solution you'd like
End-to-end in IngestFromKafkaIT: create pipeline + index with index.final_pipeline, produce messages, verify pipeline-transformed docs
Related component
No response
Describe alternatives you've considered
No response
Additional context
No response