Akka HTTP Bad Request 400 is not being traced

Description
When Akka HTTP server produces Bad Request 400 due to illegal request there is no trace produced by opentelemetry-javaagent.

Steps to reproduce
See example project https://github.com/makssobolevs/akka-open-telemetry-test

$ curl -v http://localhost:8080/%%
*   Trying 127.0.0.1:8080...
* Connected to localhost (127.0.0.1) port 8080 (#0)
> GET /%% HTTP/1.1
> Host: localhost:8080
> User-Agent: curl/7.80.0
> Accept: */*
> 
* Mark bundle as not supporting multiuse
< HTTP/1.1 400 Bad Request
< Server: akka-http/10.2.4
< Date: Sat, 15 Jan 2022 16:33:16 GMT
< Connection: close
< Content-Type: text/plain; charset=UTF-8
< Content-Length: 77
< 
* Closing connection 0

Agent config used:

 "-Dotel.resource.attributes=service.name=test",
 "-Dotel.traces.exporter=logging",
 "-Dotel.traces.sampler=always_on"

What did you expect to see?
I would expect to see span in logs with http.status_code=400

What did you see instead?
I see only akka http warning
[2022-01-15 19:33:16,844] [WARN] [akka.actor.ActorSystemImpl] [Test-akka.actor.default-dispatcher-5] [akka.actor.ActorSystemImpl(Test)] - Illegal request, responding with status '400 Bad Request': Illegal request-target: Invalid input '%', expected HEXDIG (line 1, column 3): /%%

Version
opentelemetry-javaagent 1.9.2
Akka 2.6.14
Akka HTTP 10.2.4
Scala 2.13.5
OpenJDK 11.0.13

Start by running the linked example project with opentelemetry-javaagent 1.9.2 and reproducing the curl request to /%%. Trace the Akka HTTP request path and determine where the illegal request produces the 400 response; done means a span is emitted with http.status_code=400 and the behavior is covered by a regression test.