[kubernetes] Make fingerprinting optional or make fingerprint length configurable

[kaiyan-sheng]

For users who are trying to ingest small files using the kubernetes integration might run into this error with file size is too small for ingestion:

cannot start ingesting from file "/var/log/containers/test.log": filesize of "/var/log/containers/test.log" is 594 bytes, expected at least 1024 bytes for fingerprinting: file size is too small for ingestion

We should make fingerprinting optional or make fingerprint length configurable for this use case.

prospector.scanner.fingerprint.length: 64

Original pr: https://github.com/elastic/integrations/pull/11212