Disable AssertJ's bare-named property accessor discovery

AssertJ includes a change in 3.12 that means that, by default, it now incorrectly
identifies some of the builder methods on CacheControl as accessor methods for its fields.
This commit restores the behaviour of 3.11 so that a method is only considered to be a
property accessor if a matches the Java bean naming conventions.

Closes gh-16145

Author: wilkinsona

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/reactive/WebFluxAutoConfigurationTests.java

@@ -24,6 +24,7 @@
 
 import javax.validation.ValidatorFactory;
 
+import org.assertj.core.api.Assertions;
 import org.joda.time.DateTime;
 import org.junit.Test;
 
@@ -418,6 +419,7 @@ public void cachePeriod() {
 					assertThat(handlerMap).hasSize(2);
 					for (Object handler : handlerMap.values()) {
 						if (handler instanceof ResourceWebHandler) {
+							Assertions.setExtractBareNamePropertyMethods(false);
 							assertThat(((ResourceWebHandler) handler).getCacheControl())
 									.isEqualToComparingFieldByField(
 											CacheControl.maxAge(5, TimeUnit.SECONDS));
@@ -436,6 +438,7 @@ public void cacheControl() {
 					assertThat(handlerMap).hasSize(2);
 					for (Object handler : handlerMap.values()) {
 						if (handler instanceof ResourceWebHandler) {
+							Assertions.setExtractBareNamePropertyMethods(false);
 							assertThat(((ResourceWebHandler) handler).getCacheControl())
 									.isEqualToComparingFieldByField(
 											CacheControl.maxAge(5, TimeUnit.SECONDS)