Add a nomulus renew_domain command

This may come in handy when dealing with URS requests.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=199332085

javatests/google/registry/testing/DatastoreHelper.java

@@ -316,6 +316,16 @@ public class DatastoreHelper {
         newDomainResource(domainName).asBuilder().setCreationTimeForTest(creationTime).build());
   }
 
+  public static DomainResource persistActiveDomain(
+      String domainName, DateTime creationTime, DateTime expirationTime) {
+    return persistResource(
+        newDomainResource(domainName)
+            .asBuilder()
+            .setCreationTimeForTest(creationTime)
+            .setRegistrationExpirationTime(expirationTime)
+            .build());
+  }
+
   public static DomainApplication persistActiveDomainApplication(String domainName) {
     return persistResource(newDomainApplication(domainName));
   }