[Monitoring] Parity between ops_stats_collector

[chrisronline]

Collectors are used to collector metric and usage data for use in monitoring and telemetry. We currently have two ops_stats_collector that collect low-level system details from hapi about the kibana node process.

1. https://github.com/elastic/kibana/blob/master/x-pack/plugins/monitoring/server/kibana_monitoring/collectors/get_ops_stats_collector.js
2. https://github.com/elastic/kibana/blob/master/src/server/status/collectors/get_ops_stats_collector.js

The x-pack one (1) is used for internal monitoring collection and the latter (2) is used for telemetry and the /api/stats REST endpoint.

They are used for the same thing, yet there are discrepancies in how they work. @tsullivan mentioned details related to rolling up the data and collection intervals, but I'm hoping we can still apply those nuances around the same collector.

We recently had to fix something here: #28605

[elasticmachine]

Pinging @elastic/stack-monitoring