4.x: Http2WebClientTest#multiplexParallelStreamsGet fails intermittently

[danielkec]

Enable and fix intermittent io.helidon.nima.http2.webclient.Http2WebClientTest#multiplexParallelStreamsGet

[barchetta]

Have seen it fail on the pipeline also:

[INFO] Running io.helidon.nima.http2.webclient.Http2WebClientTest
Error:  Tests run: 12, Failures: 0, Errors: 1, Skipped: 0, Time elapsed: 13.371 s <<< FAILURE! - in io.helidon.nima.http2.webclient.Http2WebClientTest
Error:  io.helidon.nima.http2.webclient.Http2WebClientTest.multiplexParallelStreamsGet(String, LazyValue)[1]  Time elapsed: 10.067 s  <<< ERROR!
java.util.concurrent.ExecutionException: io.helidon.nima.http2.webclient.StreamTimeoutException: No data received on stream 3 within the timeout PT10S
	at java.base/java.util.concurrent.CompletableFuture.reportGet(CompletableFuture.java:396)
	at java.base/java.util.concurrent.CompletableFuture.get(CompletableFuture.java:2096)
	at io.helidon.nima.http2.webclient.Http2WebClientTest.multiplexParallelStreamsGet(Http2WebClientTest.java:269)
	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
	at java.base/java.lang.reflect.Method.invoke(Method.java:580)
	at org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:727)
	at org.junit.jupiter.engine.execution.MethodInvocation.proceed(MethodInvocation.java:60)
	at org.junit.jupiter.engine.execution.InvocationInterceptorChain$ValidatingInvocation.proceed(InvocationInterceptorChain.java:131)
	at org.junit.jupiter.api.extension.InvocationInterceptor.interceptTestTemplateMethod(InvocationInterceptor.java:152)

. . .

Caused by: io.helidon.nima.http2.webclient.StreamTimeoutException: No data received on stream 3 within the timeout PT10S
	at io.helidon.nima.http2.webclient.StreamBuffer.poll(StreamBuffer.java:47)
	at io.helidon.nima.http2.webclient.Http2ClientStream.readOne(Http2ClientStream.java:271)
	at io.helidon.nima.http2.webclient.Http2ClientStream.read(Http2ClientStream.java:205)
	at io.helidon.nima.http2.webclient.Http2ClientStream.read(Http2ClientStream.java:200)
	at io.helidon.nima.http2.webclient.Http2CallChainBase$RequestingInputStream.ensureBuffer(Http2CallChainBase.java:273)
	at io.helidon.nima.http2.webclient.Http2CallChainBase$RequestingInputStream.read(Http2CallChainBase.java:261)
	at java.base/java.io.InputStream.read(InputStream.java:220)
	at io.helidon.nima.http2.webclient.Http2ClientResponseImpl.readBytes(Http2ClientResponseImpl.java:91)
	at io.helidon.nima.http.media.ReadableEntityBase$RequestingInputStream.ensureBuffer(ReadableEntityBase.java:238)
	at io.helidon.nima.http.media.ReadableEntityBase$RequestingInputStream.read(ReadableEntityBase.java:226)
	at java.base/java.io.InputStream.readNBytes(InputStream.java:412)
	at io.helidon.nima.http2.webclient.Http2WebClientTest.lambda$multiplexParallelStreamsGet$13(Http2WebClientTest.java:251)
	at io.helidon.nima.http2.webclient.Http2WebClientTest.lambda$multiplexParallelStreamsGet$15(Http2WebClientTest.java:266)
	at java.base/java.util.concurrent.CompletableFuture$AsyncRun.run(CompletableFuture.java:1804)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1144)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:642)
	at java.base/java.lang.Thread.run(Thread.java:1583)