Make gRPC Core as plugin of gRPC ObjC wrapper

Skip timer test when running under event manager

Update googletest version to master

Run generate_projects.sh

Increase timeout for macos/grpc-node test to 120 minutes

cfstream_test: workaround Apple CFStream bug

  Added test for timer wakeups

Remove nanopb from gRPC

Add gnossen and remove vjpai as bazel/** owner.

Add run: false to grpclb_fallback_test in build.yaml

Fix issue/PR template

Add v1.22.1 to interop matrix

use stricter memory order in client_idle_filter

Enforce abstract class rule

Fix warnings to unblock gcc8 support

Ignore Visual Studio Code configurations

 Make default vtable for pointer argumnet a constant

Fixing gcc8's no-unknown-warning-option issue.

Add v1.23.0 to interop matrix

Gracefully handle errors from Future object callbacks.

Repo stats tracking

In https://github.com/grpc/grpc/issues/19910, it was pointed out that
raising an exception from a Future callback would cause the channel spin
thread to terminate. If there are outstanding events on the channel,
this will cause calls to Channel.close() to block indefinitely.

This commit ensures that the channel spin thread does not die. Instead,
exceptions will be logged at ERROR level.

Fix warning in client_idle_filter.cc to support gcc8