Fix binding detection of ConfigurationProperties contributed by @Bean

This commit makes sure that a ConfigurationProperties type contributed
by a `@Bean` factory method uses properties binding regardless of the
presence of a matching constructor.

`@Bean` method makes sure the user is in control and will be responsible
of creating the instance. As a result, binding of properties will not
happen there and therefore can only happen with regular JavaBean
accessors.

Closes gh-18184

spring-boot-project/spring-boot-tools/spring-boot-configuration-processor/src/main/java/org/springframework/boot/configurationprocessor/PropertyDescriptorResolver.java

@@ -51,6 +51,9 @@ class PropertyDescriptorResolver {
 	 */
 	Stream<PropertyDescriptor<?>> resolve(TypeElement type, ExecutableElement factoryMethod) {
 		TypeElementMembers members = new TypeElementMembers(this.environment, type);
+		if (factoryMethod != null) {
+			return resolveJavaBeanProperties(type, factoryMethod, members);
+		}
 		ExecutableElement constructor = resolveConstructor(type);
 		if (constructor != null) {
 			return resolveConstructorProperties(type, factoryMethod, members, constructor);