message: fix compile_time_options by setting idle_timeout in common_http_protocol_options
  This fixes compile_time_options by setting `idle_timeout` in `common_http_protocol_options`, rather than using the deprecated `idle_timeout` field in the HCM config.
diff: @@ -511,7 +511,7 @@ void ConfigHelper::setDownstreamHttpIdleTimeout(std::chrono::milliseconds timeou
  addConfigModifier(
  [timeout](
  envoy::config::filter::network::http_connection_manager::v2::HttpConnectionManager& hcm) {
  - hcm.mutable_idle_timeout()->MergeFrom(
  + hcm.mutable_common_http_protocol_options()->mutable_idle_timeout()->MergeFrom(
  ProtobufUtil::TimeUtil::MillisecondsToDuration(timeout.count()));
  });
  }
  