Remove double wrapping of UnmodifiableMap

Author: RanVaknin

test/dynamodb-mapper-v2/src/main/java/software/amazon/awssdk/dynamodb/datamodeling/DynamoDBMapper.java

@@ -23,6 +23,7 @@
 import software.amazon.awssdk.services.dynamodb.model.GetItemResponse;
 
 import java.util.Collections;
+import java.util.HashMap;
 import java.util.Map;
 
 /**
@@ -86,7 +87,7 @@ public <T> T load(T keyObject, DynamoDBMapperConfig config) {
         }
 
         T object = privateMarshallIntoObject(
-                toParameters(itemAttributes, clazz, tableName, config));
+                toParameters(new HashMap<>(itemAttributes), clazz, tableName, config));
 
         return object;
     }