feat: decrease stack traces min duration

[rogercoll]

Changes

• Decrease default minimum duration for stack traces (5ms to 2ms) to ease the visualization in Kibana.
• Add the Java agent to Kafka service

Merge Requirements

For new features contributions please make sure you have completed the following
essential items:

• CHANGELOG.md updated to document new feature additions
• Appropriate documentation updates in the docs
• Appropriate Helm chart updates in the helm-charts

Maintainers will not merge until the above have been completed. If you're unsure
which docs need to be changed ping the
@open-telemetry/demo-approvers.

[ChrsMark]

LGTM