jagadesh24m,
Thank you for the response.
Unfortunately, the post was up so long without any responses I 'broke down' and allowed the OS update.
Initially when attempting to launch Android Auto after the update it appeared that I was worse off then previously as AA did not launch and my Pixel 2XL was jumping from 'USB charging' to another status every few seconds which was not something I had experienced before. I ended up un-installing AA and 'forgetting' the settings for each vehicle and then re-installed and re-initialized and now AA is working as it should for the first time since late December 2017. If you are still experiencing issues try uninstalling AA and forgetting any vehicle settings, then reinstall. If that still fails I would do a Factory Data Reset and then try again...