Always require acknowledgment of premium fees

This removes the configuration ability on both Registry and Registrar entities
to allow operations on premium domains to succeed without acking the fees using
the fee extension. We only ever used this ability during the minna launch, and
it was a fiasco. We have no intention of ever allowing creation, renewal,
transfer, restoring, etc. of premium domains without acking the fees ever again,
and haven't done so since 2013, so removing this ability allows us to simplify
our code, data model, and tests.

Note that all TLDs in our production system currently require price ACKing
anyway, so from an external partner perspective this commit is a noop.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=229423650

java/google/registry/model/registrar/Registrar.java

@@ -394,13 +394,6 @@ public class Registrar extends ImmutableObject implements Buildable, Jsonifiable
    */
   boolean contactsRequireSyncing = true;
 
-  /** Whether the registrar must acknowledge the price to register non-standard-priced domains. */
-  boolean premiumPriceAckRequired;
-
-  public boolean getPremiumPriceAckRequired() {
-    return premiumPriceAckRequired;
-  }
-
   @NonFinalForTesting
   private static Supplier<byte[]> saltSupplier =
       () -> {
@@ -593,7 +586,6 @@ public class Registrar extends ImmutableObject implements Buildable, Jsonifiable
         .put("emailAddress", emailAddress)
         .put("whoisServer", getWhoisServer())
         .put("blockPremiumNames", blockPremiumNames)
-        .put("premiumPriceAckRequired", premiumPriceAckRequired)
         .put("url", url)
         .put("icannReferralEmail", getIcannReferralEmail())
         .put("driveFolderId", driveFolderId)
@@ -866,11 +858,6 @@ public class Registrar extends ImmutableObject implements Buildable, Jsonifiable
       return this;
     }
 
-    public Builder setPremiumPriceAckRequired(boolean premiumPriceAckRequired) {
-      getInstance().premiumPriceAckRequired = premiumPriceAckRequired;
-      return this;
-    }
-
     /** Build the registrar, nullifying empty fields. */
     @Override
     public Registrar build() {