Add sys_monitoring query param to fleet oas

[daemitus]

Summary

I'm upstreaming some issues I've noticed in the elasticstack Terraform provider.

Adds the missing sys_monitoring query param to oas.
POST /api/fleet/agent_policies?sys_monitoring=true

See:

• https://github.com/elastic/kibana/blob/main/x-pack/plugins/fleet/server/routes/agent_policy/handlers.ts#L294
• Apply the sys_monitoring attribute during creation terraform-provider-elasticstack#792

Checklist

Delete any items that are not applicable to this PR.

• Any text added follows EUI's writing guidelines, uses sentence case text and includes i18n support

For maintainers

• This was checked for breaking API changes and was labeled appropriately

[elasticmachine]

Pinging @elastic/fleet (Team:Fleet)

[kpollich]

Thanks for the PR @daemitus, and for your help on the Terraform provider issue we chatted on previously.

@juliaElastic - Do we need to update the router code for this now that we're using the code-gen tool for OpenAPI specs?

[daemitus]

if something is generating parts of the oas docs, point me to it. I want to pull in the rest of the fixes in the terraform provider at some point.

[juliaElastic]

This is the issue that will enable generating oas, see the linked pull requests. #184685

sys_monitoring is already there in the request schema code:

kibana/x-pack/plugins/fleet/server/types/rest_spec/agent_policy.ts

Line 73 in 932614a

sys_monitoring: schema.maybe(schema.boolean()),

[daemitus]

I can look into using this, looks like it's going to get merged shortly.

[daemitus]

as a sidenote @juliaElastic , is the operationID editable in the rest_spec such that it shows up downstream in the generated oas? You're losing alot of nuance with "operationID": ''%2Fapi%2Ffleet%2Fepm%2Fpackages%2F%7BpkgName%7D%2F%7BpkgVersion%7D#3" where-as the current output has

operationId: install-package 
summary: Install package

Looks like the docs here use summary and maybe opID, or just the summary kebab-cased together.