Summary:
This only implement the server streaming RPC.
We'll need bidirectional one eventually, but that's left for future task.

Test Plan: Manual run

Reviewers: oazizi, #engineering

Reviewed By: oazizi, #engineering

JIRA Issues: PP-1897

Differential Revision: https://phab.corp.pixielabs.ai/D4929

GitOrigin-RevId: 6c1df0bcaaf34bd7d610c545bd2030a8fb26ef77