Refactor out creation of server TRIDs so they can be tested

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=152837185

javatests/google/registry/rde/DomainResourceToXjcConverterTest.java

@@ -352,7 +352,7 @@ public class DomainResourceToXjcConverterTest {
                 Key.create(billingEvent)))
             .setTransferRequestTime(DateTime.parse("1919-01-01T00:00:00Z"))
             .setTransferStatus(TransferStatus.PENDING)
-            .setTransferRequestTrid(Trid.create("client trid"))
+            .setTransferRequestTrid(Trid.create("client-trid", "server-trid"))
             .build())
         .build();
     clock.advanceOneMilli();