Add the START_DATE_SUNRISE phase

The START_DATE_SUNRISE phase allows registration of domains only with a signed mark. In all other respects - it is identical to the GENERAL_AVAILABILITY phase.

Note that Anchor Tenants bypass all checks, and are hence able to register domains without a signed mark.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=185534793

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

@@ -105,7 +105,8 @@ public final class DomainCheckFlow implements Flow {
    * unavailable.
    */
   private static final ImmutableSet<TldState> PENDING_ALLOCATION_TLD_STATES =
-      Sets.immutableEnumSet(TldState.GENERAL_AVAILABILITY, TldState.QUIET_PERIOD);
+      Sets.immutableEnumSet(
+          TldState.GENERAL_AVAILABILITY, TldState.START_DATE_SUNRISE, TldState.QUIET_PERIOD);
 
   @Inject ResourceCommand resourceCommand;
   @Inject ExtensionManager extensionManager;