Revert #19704 and #20060

This reverts commit ac5f8062, reversing
changes made to 8ae54943.

Tune load reporter test

LB policy API changes suggested by Sanjay.

Add auditwheel to linux docker

Run auditwheel-show to python artifacts

Replace 32bit/debian:jessie with i386/debian:jessie

Use opencensus::tags::TagKey.

Make python dockerfiles buildable again

Fixed init-order-fiasco for static slice table.

ability to set grpc proxy with no effect on http proxy

Switch py_proto_library from using src to deps to conform with google3

Fixes init-order bug affecting https://github.com/grpc/grpc/issues/19819 which
was first exposed by this commit:
https://github.com/grpc/grpc/commit/857375a1420df184963ed83f638dd21ea359aa37

Update doc to use clang-5.0

Confirm that generic API method name is not needed after call creation

Fix type unmatch

Remove CreateChannel() method from LB helper API.

Update triage rotation

Only run libuv portability tests as build-only

Stop the failing Python LocalCredentials test on Windows

return unavailable on transport closed

Added GRPC_USE_CPP_STD_LIB flag

ProtoRPC include some headers

Fix hpack parser fuzzer failure.

Rename gettid() functions.

Implemented _abort method on ServicerContext