[Enhancement][Search Relevance] Add additional users to be able to work

Is your feature request related to a problem? Please describe.
I was walking @arunagov through the SRW and discovered that she I think have permissions to run an experiment:

[security_exception] no permissions for [cluster:admin/opensearch/search_relevance/experiment/create] and User [name=arunagov, backend_roles=[offline_access, default-roles-opensearch-nightly-playgrounds, uma_authorization], requestedTenant=__user__]

Describe the solution you'd like
I would like to have @arunagov, @wrigleyDan, and @janellearita and @arjunkumargiri added to be able to run Experiments. These are all their Github user ids.

Describe alternatives you've considered
Do we need to work on a more generic approach that lets us modify a file as a PR to add people?

Additional context
We're excited to get more people showing off SRW and learning how to use it.