Summary: TSIA. This code still doesn't support joins or unions for the pushdown, that will come in a subsequent diff.

Test Plan: existing/added

Reviewers: philkuz, jamesbartlett, zasgar, #engineering

Reviewed By: philkuz, #engineering

JIRA Issues: PP-1811

Differential Revision: https://phab.corp.pixielabs.ai/D4762

GitOrigin-RevId: 8d58c056fc49bc62f48ba7cc71a606e1ac060087