Tolerate race condition in httpRequestsAreTimed

Tomcat 11 will [1] send a response as soon as Content-Length bytes has
been written. This initiates a race between the timer being registered
on the server side and the test receiving the response and looking for
the timer.

Rather than sleeping for a fix period of time, we now use Awaitility
to await the availability of the timer.

Closes gh-48049

[1] apache/tomcat@69eff83

Author: wilkinsona

module/spring-boot-jersey/src/test/java/org/springframework/boot/jersey/autoconfigure/metrics/JerseyServerMetricsAutoConfigurationTests.java

@@ -17,6 +17,7 @@
 package org.springframework.boot.jersey.autoconfigure.metrics;
 
 import java.net.URI;
+import java.time.Duration;
 
 import io.micrometer.core.instrument.MeterRegistry;
 import io.micrometer.core.instrument.Timer;
@@ -26,6 +27,8 @@
 import jakarta.ws.rs.GET;
 import jakarta.ws.rs.Path;
 import jakarta.ws.rs.PathParam;
+import org.assertj.core.api.InstanceOfAssertFactories;
+import org.awaitility.Awaitility;
 import org.glassfish.jersey.micrometer.server.ObservationApplicationEventListener;
 import org.glassfish.jersey.server.ResourceConfig;
 import org.junit.jupiter.api.Test;
@@ -84,10 +87,14 @@ void shouldProvideAllNecessaryBeans() {
 	void httpRequestsAreTimed() {
 		this.webContextRunner.withUserConfiguration(MetricsConfiguration.class).run((context) -> {
 			doRequest(context);
-			Thread.sleep(500);
 			MeterRegistry registry = context.getBean(MeterRegistry.class);
-			Timer timer = registry.get("http.server.requests").tag("uri", "/users/{id}").timer();
-			assertThat(timer.count()).isOne();
+			// Response is sent before the timer is registered which triggers a race
+			// condition.
+			// https://github.com/apache/tomcat/commit/69eff83577f7c00cbaaca9384ab4b1989f516797
+			Awaitility.await().atMost(Duration.ofSeconds(5)).untilAsserted(() -> {
+				Timer timer = registry.find("http.server.requests").tag("uri", "/users/{id}").timer();
+				assertThat(timer).isNotNull().extracting(Timer::count, InstanceOfAssertFactories.LONG).isOne();
+			});
 		});
 	}