Handle SPECIFIED renewal price w/token in check flow (#2651)

This is kinda nonsensical because this use case is trying to apply a
single use token multiple times in the same domain:check request --
like, trying to use a single-use token for both create, renew, and
transfer while having a $0 create price and a premium renewal price.

This change doesn't affect any actual business / costs, since SPECIFIED
token renewal prices were already set on the BillingRecurrence

core/src/main/java/google/registry/flows/domain/DomainPricingLogic.java

@@ -287,6 +287,9 @@ public final class DomainPricingLogic {
           || token.getRenewalPriceBehavior().equals(RenewalPriceBehavior.NONPREMIUM)) {
         return tld.getStandardRenewCost(dateTime).multipliedBy(years);
       }
+      if (token.getRenewalPriceBehavior().equals(RenewalPriceBehavior.SPECIFIED)) {
+        return token.getRenewalPrice().get();
+      }
     }
     return getDomainCostWithDiscount(
         domainPrices.isPremium(),