grpc-java fails to build against protobuf 3.21

[jvolkman]

What version of gRPC-Java are you using?

1.46.0

What is your environment?

Linux, Macos, protobuf v3.21

What did you expect to see?

A successful build

What did you see instead?

grpc-java fails to build:

external/io_grpc_grpc_java/compiler/src/java_plugin/cpp/java_generator.cpp:25:10: fatal error: 'google/protobuf/compiler/java/java_names.h' file not found
#include <google/protobuf/compiler/java/java_names.h>
         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.

Steps to reproduce the bug

Attempt to build grpc-java against protobuf 3.21

This commit in upstream protobuf renamed java_names.h to names.h, which is included by compiler/src/java_plugin/cpp/java_generator.cpp

[YifeiZhuang]

protobuf needs upgrade, currently it is 3.19.2