It was silly mistake during the deployer config. The XO deployer pipelins configs should have been placed after the Tridion-Commit-TX pipe line, instead I have placed the same at the end. Thanks Brian from SDL support for noticing the same.
A couple of failure points that you can look at for your implementation would be your start up parameters for your deployer to include es-host and es-port highlighted below.
--es.host=10.100.101.52 (Elasticsearch server)
--es.port=9200 (port number of the Elasticsearch)
A quick verification would be to also check if the add-on is deployed ...
This issue was resolved by referencing session_cartridge.jar and session_cartridge_conf.xml file in content service. Details about how to reference session cartride can be found at https://docs.sdl.com/792149/602448/sdl-tridion-sites-9/adding-the-session-cartridge-to-support-footprints. Post referencing mentioned Jar and XML file, I can now see the OOTB ...