Update GoogleChat documenation

What does this MR do and why?

This MR updates IntegrationGoogle Chat (Hangouts) documentation with in-line reply support.

MR acceptance checklist

Please evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

Screenshots or screen recordings

Screenshots are required for UI changes, and strongly recommended for all other merge requests.

How to set up and validate locally

N/A