Google is preparing to integrate Google Messages RCS to work with Samsung’s Continuity feature. This feature lets Samsung Tablet and Smartwatch users receive calls and messages from a Samsung smartphone. The new integration would let the Continuity feature access incoming RCS messages and let users respond while using Google Messages. Samsung Galaxy S21 Ultra XDA-Developers discovered this through the strings of text contained in the Android Messages app code. The text refers to a new permission within the app. Permission to send SMS/MMS/RCS messages using Android Messages API...
Source: https://www.gsmarena.com/google_messages_prepares_rcs_integration_with_samsung_continuity-news-49983.php
