Fail on failed write

Add zalloc, convert a bunch of files to use it

Add more cq benchmarks

Client-side keepalive pings

Make portability tests pull images from Dockerhub and add test filter

Stop receiving and add an error to batch when there is an error from lower level.

Upmerge 1.1.x into master

Display logs when running interop based tests

Based on soltanmm-google's #9114

Fix uploader

Add benchmarks for metadata operations

Add benchmarks for HTTP2 HPACK encoding

Increase timeout for bm_fullstack

Add grpc_load_reporting to grpc_cronet

Fix closure running: current code is unsafe

Fix interop HTML report

Bazel BUILD files tests under `test/core/surface` and `test/cpp/end2end`

Reduce mutexes in grpc_fd  read_closure/write_closure/shutdown paths (epoll engine only)

Add experimental CI job to run sanity tests

Make load balancers use combiner locks