No one else has tried implementing the RCS standard. There just aren't any open-source Android libraries for RCS out there, much less anything in AOSP. https:

No one else has tried implementing the RCS standard. There just aren't any open-source Android libraries for RCS out there, much less anything in AOSP. https://github.com/search?q=rcs+android&type=repositories https://github.com/search?q=rcs+android&type=repositories