[Parity] Monitoring to include cpuacct and cpu in kibana_stats

[igoristic]

Parity test fails with build ES_BUILD_URL=https://snapshots.elastic.co/8.0.0-94e4ba96

09:22:08 ERROR: Metricbeat-indexed doc for type='kibana_stats' has unexpected deletion: kibana_stats.os.cpuacct
09:22:08 ERROR: Metricbeat-indexed doc for type='kibana_stats' has unexpected deletion: kibana_stats.os.cpu

Because of elastic/kibana#76730

Stack Monitoring kibana server side code does not use these values (yet), but we might consider using them with additional (ongoing) out of the box alerting feature (in the near future).

[elasticmachine]

Pinging @elastic/stack-monitoring (Stack monitoring)

[elasticmachine]

Pinging @elastic/integrations-services (Team:Services)

[smith]

Not prioritizing this at this time.