Modified isKotlinClass determination method

The kotlin-reflect method was used as a reference https://github.com/JetBrains/kotlin/blob/c4fc0b919dfe9b746f9ecfcc08668fa05b839064/core/reflection.jvm/src/kotlin/reflect/jvm/internal/KClassImpl.kt#L59

Author: k163377

src/main/kotlin/com/fasterxml/jackson/module/kotlin/KotlinModule.kt

@@ -14,11 +14,7 @@ import com.fasterxml.jackson.module.kotlin.SingletonSupport.DISABLED
 import java.util.*
 import kotlin.reflect.KClass
 
-private const val metadataFqName = "kotlin.Metadata"
-
-fun Class<*>.isKotlinClass(): Boolean {
-    return declaredAnnotations.any { it.annotationClass.java.name == metadataFqName }
-}
+fun Class<*>.isKotlinClass(): Boolean = this.isAnnotationPresent(Metadata::class.java)
 
 /**
  * @param   reflectionCacheSize     Default: 512.  Size, in items, of the caches used for mapping objects.