[httpjson] Render of auth.oauth2.scopes fails #3295

Given this rendering template currently in use to generate auth.oauth2.scopes,

auth.oauth2.scopes:
{{#each oauth_scopes as |scope i|}}
  - {{scope}}
{{/each}}

And this input format definition in the manifest,

      - name: oauth_scopes
        type: yaml
        title: Oauth2 Scopes
        description: A list of scopes that will be requested during the oauth2 flow. It is optional for all providers.
        show_user: false
        multi: true
        required: false

YAML format text input is enforced in Kibana and via API request, e.g. the string has to be either "- scope_thing" or "['scope_thing']" to be accepted by the API

In all cases, regardless of input, the "compiled_stream" output will result in "auth.oauth2.scopes": null,