Support instantiating Kotlin classes with optional parameters

This commit updates BeanUtils class in order to add Kotlin optional
parameters with default values support to the immutable data classes
support introduced by SPR-15199.

Issue: SPR-15673

spring-core/src/main/java/org/springframework/core/MethodParameter.java

@@ -31,7 +31,6 @@ import java.util.Map;
 import java.util.Optional;
 import java.util.stream.Collectors;
 
-import kotlin.Metadata;
 import kotlin.reflect.KFunction;
 import kotlin.reflect.KParameter;
 import kotlin.reflect.jvm.ReflectJvmMapping;
@@ -737,7 +736,7 @@ public class MethodParameter {
 		 * Check whether the specified {@link MethodParameter} represents a nullable Kotlin type or not.
 		 */
 		public static boolean isNullable(MethodParameter param) {
-			if (param.getContainingClass().isAnnotationPresent(Metadata.class)) {
+			if (isKotlinClass(param.getContainingClass())) {
 				Method method = param.getMethod();
 				Constructor<?> ctor = param.getConstructor();
 				int index = param.getParameterIndex();
@@ -767,6 +766,16 @@ public class MethodParameter {
 			}
 			return false;
 		}
+
+		private static boolean isKotlinClass(Class<?> clazz) {
+			for (Annotation annotation : clazz.getDeclaredAnnotations()) {
+				if (annotation.annotationType().getName().equals("kotlin.Metadata")) {
+					return true;
+				}
+			}
+			return false;
+		}
+		
 	}
 
 }