AWS is updating its CodeBuild service to require the additional parameter on build. The background is that AWS will be changing the OS on which they run CodeBuild processing. Once they switch over to the new OS, that OS will require the overlay2 driver rather than the current driver and overlay2 requires the extra parameter for VOLUME. Without it, the container will probably fail.
I cannot say how prevalent the use of the Selenium containers is within AWS CodeBuild. I only know that we make regular use of them for Smoke Tests on service updates and would really prefer to continue using the builds from DockerHub. Right now, because of concern for lost functionality, we are debating creating our own. I'm really hoping the changes might be either already in the current builds or easily added so that we can continue to use the DockerHub versions.
Hope that explains things a bit more.