Test UnknownCurrencyEppException in the flow tests

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=239279335

java/google/registry/flows/FlowUtils.java

@@ -114,7 +114,7 @@ public final class FlowUtils {
   }
 
   /** Unknown currency. */
-  static class UnknownCurrencyEppException extends ParameterValueRangeErrorException {
+  public static class UnknownCurrencyEppException extends ParameterValueRangeErrorException {
     public UnknownCurrencyEppException() {
       super("Unknown currency.");
     }

java/google/registry/flows/domain/DomainCheckFlow.java

@@ -77,6 +77,7 @@ import org.joda.time.DateTime;
  * <p>This flow also supports the EPP fee extension and can return pricing information.
  *
  * @error {@link google.registry.flows.exceptions.TooManyResourceChecksException}
+ * @error {@link google.registry.flows.FlowUtils.UnknownCurrencyEppException}
  * @error {@link DomainFlowUtils.BadDomainNameCharacterException}
  * @error {@link DomainFlowUtils.BadDomainNamePartsCountException}
  * @error {@link DomainFlowUtils.DomainNameExistsAsTldException}

java/google/registry/flows/domain/DomainCreateFlow.java

@@ -123,6 +123,7 @@ import org.joda.time.Duration;
  * @error {@link google.registry.flows.exceptions.ResourceAlreadyExistsException}
  * @error {@link google.registry.flows.EppException.UnimplementedExtensionException}
  * @error {@link google.registry.flows.ExtensionManager.UndeclaredServiceExtensionException}
+ * @error {@link google.registry.flows.FlowUtils.UnknownCurrencyEppException}
  * @error {@link DomainCreateFlow.AnchorTenantCreatePeriodException}
  * @error {@link DomainCreateFlow.MustHaveSignedMarksInCurrentPhaseException}
  * @error {@link DomainCreateFlow.NoGeneralRegistrationsInCurrentPhaseException}

java/google/registry/flows/domain/DomainInfoFlow.java

@@ -63,6 +63,7 @@ import org.joda.time.DateTime;
  * domain, will get a rich result with all of the domain's fields. All other requests will be
  * answered with a minimal result containing only basic information about the domain.
  *
+ * @error {@link google.registry.flows.FlowUtils.UnknownCurrencyEppException}
  * @error {@link google.registry.flows.ResourceFlowUtils.BadAuthInfoForResourceException}
  * @error {@link google.registry.flows.ResourceFlowUtils.ResourceDoesNotExistException}
  * @error {@link DomainFlowUtils.BadPeriodUnitException}

java/google/registry/flows/domain/DomainRenewFlow.java

@@ -92,6 +92,7 @@ import org.joda.time.Duration;
  * longer than 10 years unless it comes in at the exact millisecond that the domain would have
  * expired.
  *
+ * @error {@link google.registry.flows.FlowUtils.UnknownCurrencyEppException}
  * @error {@link google.registry.flows.ResourceFlowUtils.ResourceDoesNotExistException}
  * @error {@link google.registry.flows.ResourceFlowUtils.ResourceNotOwnedException}
  * @error {@link google.registry.flows.exceptions.ResourceStatusProhibitsOperationException}

java/google/registry/flows/domain/DomainRestoreRequestFlow.java

@@ -92,6 +92,7 @@ import org.joda.time.DateTime;
  * original expiration time was.
  *
  * @error {@link google.registry.flows.EppException.UnimplementedExtensionException}
+ * @error {@link google.registry.flows.FlowUtils.UnknownCurrencyEppException}
  * @error {@link google.registry.flows.ResourceFlowUtils.ResourceDoesNotExistException}
  * @error {@link google.registry.flows.ResourceFlowUtils.ResourceNotOwnedException}
  * @error {@link DomainFlowUtils.CurrencyUnitMismatchException}

java/google/registry/flows/domain/DomainTransferRequestFlow.java

@@ -92,6 +92,7 @@ import org.joda.time.DateTime;
  * rejection or cancellation of the request, they will be deleted (and in the approval case,
  * replaced with new ones with the correct approval time).
  *
+ * @error {@link google.registry.flows.FlowUtils.UnknownCurrencyEppException}
  * @error {@link google.registry.flows.ResourceFlowUtils.BadAuthInfoForResourceException}
  * @error {@link google.registry.flows.ResourceFlowUtils.ResourceDoesNotExistException}
  * @error {@link google.registry.flows.exceptions.AlreadyPendingTransferException}