Log Message:
Update sysutils/beats to 6.0.1.

Affecting all Beats
- Fix documentation links in README.md files.
- Fix add_docker_metadata dropping some containers.

Heartbeat
- Fix the "HTTP up status" visualization.

Metricbeat
- Fix map overwrite in docker diskio module.
- Fix connection leak in mongodb module.
- Fix the include top N processes feature for cases where there
  are fewer processes than N.