Spans without http.status_code attribute created by http-url-connection instrumentation

Description

Spans for HTTP calls made using HttpURLConnection or a client like RestTemplate from Spring Boot, which uses it, have no http.status_code attribute on errors with response status 4xx and 5xx. If a response has status 1xx, 2xx or 3xx the attribute is present.

Status 1xx, 2xx and 3xx	Status 4xx and 5xx

Steps to reproduce

1. Build the project with mvn clean package.
2. Start the service, httpbin and jaeger using docker-compose up -d and wait until all components are started.
3. Call ./calls.sh script to perform some HTTP calls to the service.
4. Take a look at traces in jaeger UI - http://localhost:16686.
5. Stop all components using docker-compose down.

Alternatively the service could be started without docker:

1. Build the project with mvn -Dexec.skip clean package.
2. Start the service:

java -javaagent:path/to/opentelemetry-javaagent-all.jar \
       -Dotel.traces.exporter=logging \
       -Dotel.metrics.exporter=none \
       -jar target/opentelemetry-span-without-status-1.0.0.jar \
       --httpbin.uri=https://httpbin.org/status

3. Call ./calls.sh script to perform some HTTP calls to the service.