[system benchmarking] "Hostname" and "Port" placeholders evaluate to empty strings in scenario definition

[navnit-elastic]

The documentation here mentions that the "Hostname" and "Port" placeholders are available for use in a data stream's <scenario>.yml file. However, in the package policy, they seems to evaluate to an empty string.

Scenario Definition:

---
description: Benchmark 100000 activity events ingested
input: httpjson
vars:
  url: http://{{Hostname}}:{{Port}}
  api_token: xxxx
  enable_request_tracer: true
data_stream:
  name: activity
  vars:
    preserve_original_event: true
warmup_time_period: 2s
corpora:
  input_service:
    name: sentinel_one
  generator:
    total_events: 100000
    template:
      path: ./activity-benchmark/template.ndjson
      type: gotext
    config:
      path: ./activity-benchmark/config.yml
    fields:
      path: ./activity-benchmark/fields.yml

Evaluated Package Policy:

{"name":"","description":"","namespace":"ep","policy_id":"ef2fbf1a-a08f-4334-91e8-1c94c19d2cef","package":{"name":"sentinel_one","version":"1.37.0"},"inputs":{"sentinel_one-httpjson":{"enabled":true,"vars":{"api_token":"xxxx","enable_request_tracer":true,"url":"http://:0"},"streams":{"sentinel_one.activity":{"enabled":true,"vars":{"preserve_original_event":true}}}}},"force":true}