Migrate getCreatePrice() call to DomainPricingLogic

Swap all calls to TldSpecificLogicProxy.getCreatePrice() to the counterpart in
DomainPricingLogic. Also makes necessary changes for testing to work, including
fake implementations of DomainPricingCustomLogic and
DomainCreateLofwCustomLogic.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=140754334

javatests/google/registry/flows/custom/TestDomainApplicationCreateFlowCustomLogic.java

@@ -0,0 +1,63 @@
+// Copyright 2016 The Nomulus Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package google.registry.flows.custom;
+
+import com.google.common.base.Joiner;
+import com.google.common.net.InternetDomainName;
+import google.registry.flows.SessionMetadata;
+import google.registry.flows.domain.DomainApplicationCreateFlow;
+import google.registry.model.domain.flags.FlagsCreateCommandExtension;
+import google.registry.model.eppinput.EppInput;
+import google.registry.model.eppoutput.CreateData.DomainCreateData;
+
+/** A class to customize {@link DomainApplicationCreateFlow} for testing. */
+public class TestDomainApplicationCreateFlowCustomLogic
+    extends DomainApplicationCreateFlowCustomLogic {
+
+  protected TestDomainApplicationCreateFlowCustomLogic(
+      EppInput eppInput, SessionMetadata sessionMetadata) {
+    super(eppInput, sessionMetadata);
+  }
+
+  private String getTld() {
+    return InternetDomainName.from(getEppInput().getTargetIds().get(0)).parent().toString();
+  }
+
+  @Override
+  public BeforeResponseReturnData beforeResponse(BeforeResponseParameters parameters) {
+    if (getTld().equals("flags")) {
+      String flagsPrefix =
+          Joiner.on('-')
+              .join(getEppInput().getSingleExtension(FlagsCreateCommandExtension.class).getFlags());
+
+      DomainCreateData resData = (DomainCreateData) parameters.resData();
+      resData =
+          DomainCreateData.create(
+              Joiner.on('-').join(flagsPrefix, resData.name()),
+              resData.creationDate(),
+              resData.expirationDate());
+
+      return BeforeResponseReturnData.newBuilder()
+          .setResData(resData)
+          .setResponseExtensions(parameters.responseExtensions())
+          .build();
+    } else {
+      return BeforeResponseReturnData.newBuilder()
+          .setResData(parameters.resData())
+          .setResponseExtensions(parameters.responseExtensions())
+          .build();
+    }
+  }
+}