This creates a new "beats_system" user and role with the same
privileges as the existing "logstash_system" user/role.
The "beat_system" user is also added as a managed user within
the "setup-passwords" command.
Users who upgrade from an earlier version of Elasticsearch/X-Pack
will need to manually set a password for the beats_system user via
the change password API (or Kibana UI)
Original commit: elastic/x-pack-elasticsearch@6087d3a18e
* [DOCS] Add SSL info to setup-passwords
* [DOCS] Addressed feedback in setup-passwords
* [DOCS] Added link to setup-passwords troubleshooting page
Original commit: elastic/x-pack-elasticsearch@2bf820c303