Merge branch 'client_channel_init_cleanup' into cpp_filter_api_cleanup

examples/cpp/helloworld/greeter_client.cc

examples/python/multiplex/run_codegen.py

examples/python/route_guide/run_codegen.py

src/compiler/csharp_generator.cc

src/core/ext/client_channel/client_channel.c

src/csharp/Grpc.Examples/MathGrpc.cs

src/csharp/Grpc.HealthCheck/HealthGrpc.cs

src/csharp/Grpc.IntegrationTesting/MetricsGrpc.cs

src/csharp/Grpc.IntegrationTesting/ServicesGrpc.cs

src/csharp/Grpc.IntegrationTesting/TestGrpc.cs

src/csharp/Grpc.Reflection/ReflectionGrpc.cs

src/python/grpcio/grpc/__init__.py

src/python/grpcio/grpc/_server.py

src/python/grpcio_health_checking/grpc/__init__.py

src/python/grpcio_health_checking/grpc_health/__init__.py

src/python/grpcio_health_checking/grpc_health/v1/__init__.py

src/python/grpcio_health_checking/grpc_health/v1/health.py

src/python/grpcio_health_checking/health_commands.py

src/python/grpcio_health_checking/setup.py

src/python/grpcio_reflection/grpc/__init__.py