Create an agent binary download source
[Required authorization] Route required privileges: fleet-settings-all.
POST /api/fleet/agent_download_sources
curl \ --request POST 'https://<KIBANA_URL>/api/fleet/agent_download_sources' \ --header "Authorization: $API_KEY" \ --header "Content-Type: application/json" \ --header "kbn-xsrf: true" \ --data '{"host":"https://example.com","id":"string","is_default":false,"name":"string","proxy_id":"string","secrets":{"ssl":{"key":{"id":"string"}}},"ssl":{"certificate":"string","certificate_authorities":["string"],"key":"string"}}'