[Ownership] Assign test files to viz team (elastic#200775)

## Summary

Assign test files to viz team

Contributes to: elastic#192979

.github/CODEOWNERS

@@ -1116,6 +1116,7 @@ src/plugins/discover/public/context_awareness/profile_providers/security @elasti
 /x-pack/test/screenshot_creation @elastic/platform-docs
 
 # Visualizations
+/test/functional/page_objects/unified_search_page.ts @elastic/kibana-visualizations # Assigned per https://github.com/elastic/kibana/pull/200132#discussion_r1847188168
 /test/functional/apps/getting_started/*.ts @elastic/kibana-visualizations # Assigned per https://github.com/elastic/kibana/pull/199767#discussion_r1840485031
 /x-pack/test/upgrade/apps/graph @elastic/kibana-visualizations
 /x-pack/test/functional/page_objects/log_wrapper.ts @elastic/kibana-visualizations # Assigned per https://github.com/elastic/kibana/pull/36437