Changing organization settings cannot happen in a unit test. Nor should be necessary to do so. You can do a generic copy of selected fields with a Set and some Maps:
Set<String> fieldsToCopy = new Set<String> { 'FirstName','MiddleName','LastName'};
Map<String, Object> valuesFromRecord = record.getPopulatedFieldsAsMap();
valuesFromRecord.keySet().retainAll(fieldsToCopy);
for(String field: valuesFromRecord) {
record2.put(field, valuesFromRecord.get(field));
}
If the field names would differ, you can also create a mapping for that as well:
Map<String, String> fieldMap = new Map<String, String> {
'FirstName' => 'MiddleName__c'
'MiddleName' => 'MiddleName__c'
'LastName' => 'MiddleName__c'
};
And:
for(String field: valuesFromRecord) {
record2.put(fieldMap.get(field), valuesFromRecord.get(field));
}