DTSPB-4517 Added different type for warnings field

Author: IswaryaPepakayala

src/main/java/uk/gov/hmcts/reform/probate/model/cases/grantofrepresentation/GrantOfRepresentationData.java

@@ -937,7 +937,7 @@ public void setGrandChildrenSurvivedOverEighteen(Boolean booleanValue) {
 
     private String expectedResponseDate;
 
-    private List<String> autoCaseWarnings;
+    private List<CollectionMember<String>> autoCaseWarnings;
 
     @JsonDeserialize(using = YesNoDeserializer.class)
     @JsonSerialize(using = YesNoSerializer.class)