Fix all uses of DateTime.now() to use DateTimeZone.UTC

Almost all uses were in test classes, which I replaced with clock.nowUTC().

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=134993149

java/google/registry/rde/RdeImportUtils.java

@@ -38,7 +38,6 @@ import java.io.InputStream;
 import javax.inject.Inject;
 import javax.xml.bind.JAXBException;
 import javax.xml.stream.XMLStreamException;
-import org.joda.time.DateTime;
 
 /**
  * Utility functions for escrow file import.
@@ -134,7 +133,7 @@ public class RdeImportUtils {
         String tld = parser.getHeader().getTld();
         try {
           Registry registry = Registry.get(tld);
-          TldState currentState = registry.getTldState(DateTime.now());
+          TldState currentState = registry.getTldState(clock.nowUtc());
           checkArgument(
               currentState == TldState.PREDELEGATION,
               String.format("Tld '%s' is in state %s and cannot be imported", tld, currentState));