Issue fix - Duplicated subproperties causing validation errors (#241)

Author: xiwhuang

python/rpdk/java/templates/POJO.java

@@ -1,6 +1,9 @@
 // This is a generated file. Modifications will be overwritten.
 package {{ package_name }};
 
+import com.fasterxml.jackson.annotation.JsonAutoDetect;
+import com.fasterxml.jackson.annotation.JsonAutoDetect.Visibility;
+import com.fasterxml.jackson.annotation.JsonIgnore;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import java.util.Map;
 import java.util.List;
@@ -15,6 +18,7 @@
 @Builder
 @AllArgsConstructor
 @NoArgsConstructor
+@JsonAutoDetect(fieldVisibility = Visibility.ANY, getterVisibility = Visibility.NONE, setterVisibility = Visibility.NONE)
 public class {{ model_name|uppercase_first_letter }} {
     {% for name, type in properties.items() %}
     @JsonProperty("{{ name }}")