Create a Fleet Server host
[Required authorization] Route required privileges: fleet-settings-all.
POST /api/fleet/fleet_server_hosts
curl \ --request POST 'https://<KIBANA_URL>/api/fleet/fleet_server_hosts' \ --header "Authorization: $API_KEY" \ --header "Content-Type: application/json" \ --header "kbn-xsrf: true" \ --data '{"host_urls":["string"],"id":"string","is_default":false,"is_internal":true,"is_preconfigured":false,"name":"string","proxy_id":"string","secrets":{"ssl":{"agent_key":{"id":"string"},"es_key":{"id":"string"},"key":{"id":"string"}}},"ssl":{"agent_certificate":"string","agent_certificate_authorities":["string"],"agent_key":"string","certificate":"string","certificate_authorities":["string"],"client_auth":"optional","es_certificate":"string","es_certificate_authorities":["string"],"es_key":"string","key":"string"}}'