Drop REVERB_PROTOC_VERSION support.
Drop REVERB_PROTOC_VERSION support.

PiperOrigin-RevId: 439575496
Change-Id: I59b4fd622c7e0090ea36d1a466c2315a63340355

deepmind/launchpad,deepmind/launchpad,deepmind/launchpad,deepmind/launchpad