Deep copy mapFields and listFields for new ZNRecord(ZNRecord record, String id)

[huizhilu]

new ZNRecord(ZNRecord record, String id) seems it wants to do a deep copy. But mapFields and listFields are not deep copied.

helix/helix-core/src/main/java/org/apache/helix/ZNRecord.java

Lines 104 to 105 in 824bc95

	mapFields.putAll(record.getMapFields());
	listFields.putAll(record.getListFields());

If deep copying is expected, we would like to fix it.