The version used by protoc-gen-grpc-java will be upgraded separately,
because of large C++ build changes necessary. But that won't impact
users at all. We are upgrading to protoc 22.3; only the grpc plugin is
not upgraded.
Bazel is upgraded for both Java and C++.
Extensive README, a server that exposes channelz and has pauses, and a client that uses multiple channels also exposes channelz service and has a 30 second delay to allow people to run the grpcdebug tool.
Fixit b/259286633