Fix regression in spring-scheduling span name

[trask]

This fixes (and adds test for) a small (unreleased) regression introduced in #5342.

[laurit]

I suspect that it might be better to attempt to unwrap the target object.

opentelemetry-java-instrumentation/instrumentation/spring/spring-integration-4.1/library/src/main/java/io/opentelemetry/instrumentation/spring/integration/TracingChannelInterceptor.java

Lines 252 to 268 in 9f00cf3

	// unwrap spring aop proxy
	// based on org.springframework.test.util.AopTestUtils#getTargetObject
	@SuppressWarnings("unchecked")
	public static <T> T unwrapProxy(T candidate) {
	try {
	if (AopUtils.isAopProxy(candidate) && candidate instanceof Advised) {
	Object target = ((Advised) candidate).getTargetSource().getTarget();
	if (target != null) {
	return (T) target;
	}
	}
	return candidate;
	} catch (Throwable ignore) {
	return candidate;
	}
	}

Unfortunately this is a common issue with getting class from object, there is no easy way to tell whether we got a proxy and how to unwrap it.

[trask]

I gave this a try, but the unwrapped class in the test I added was still EnhancedClassTaskConfig$$EnhancerByCGLIB$$b6a5b321@4ac197a7