Merge pull request #10026 from mehrdada/bump-proto-depenedency-on-python-3.2

setup.py

src/python/grpcio_health_checking/setup.py

src/python/grpcio_reflection/setup.py

src/python/grpcio_tests/setup.py

templates/tools/dockerfile/python_deps.include

tools/distrib/python/grpcio_tools/setup.py

tools/dockerfile/grpc_artifact_linux_x64/Dockerfile

tools/dockerfile/grpc_artifact_linux_x86/Dockerfile

tools/dockerfile/interoptest/grpc_interop_csharp/Dockerfile

...kerfile/interoptest/grpc_interop_csharpcoreclr/Dockerfile

tools/dockerfile/interoptest/grpc_interop_cxx/Dockerfile

tools/dockerfile/interoptest/grpc_interop_go/Dockerfile

tools/dockerfile/interoptest/grpc_interop_http2/Dockerfile

tools/dockerfile/interoptest/grpc_interop_java/Dockerfile

tools/dockerfile/interoptest/grpc_interop_node/Dockerfile

tools/dockerfile/interoptest/grpc_interop_python/Dockerfile

tools/dockerfile/interoptest/grpc_interop_ruby/Dockerfile

...kerfile/stress_test/grpc_interop_stress_csharp/Dockerfile

...dockerfile/stress_test/grpc_interop_stress_cxx/Dockerfile

.../dockerfile/stress_test/grpc_interop_stress_go/Dockerfile