Merge remote-tracking branch 'upstream/v1.4.x' into master_1.4.1_upmerge

src/core/lib/iomgr/tcp_uv.c

src/node/ext/call.cc

src/node/src/client.js

src/node/src/protobuf_js_6_common.js

src/node/test/surface_test.js

test/cpp/end2end/round_robin_end2end_test.cc

test/cpp/microbenchmarks/bm_fullstack_trickle.cc

third_party/cares/config_linux/ares_config.h

tools/dockerfile/grpc_artifact_linux_x64/Dockerfile

tools/dockerfile/grpc_artifact_protoc/Dockerfile

tools/jenkins/run_qps_diff.sh

tools/jenkins/run_trickle_diff.sh

tools/run_tests/artifacts/artifact_targets.py

tools/run_tests/artifacts/build_artifact_node.sh