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/TestCustomLogicFactory.java

@@ -0,0 +1,40 @@
+// 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 google.registry.flows.SessionMetadata;
+import google.registry.model.eppinput.EppInput;
+
+/** A custom logic factory for testing. */
+public class TestCustomLogicFactory extends CustomLogicFactory {
+
+  @Override
+  public DomainPricingCustomLogic forDomainPricing(
+      EppInput eppInput, SessionMetadata sessionMetadata) {
+    return new TestDomainPricingCustomLogic(eppInput, sessionMetadata);
+  }
+
+  @Override
+  public DomainCreateFlowCustomLogic forDomainCreateFlow(
+      EppInput eppInput, SessionMetadata sessionMetadata) {
+    return new TestDomainCreateFlowCustomLogic(eppInput, sessionMetadata);
+  }
+
+  @Override
+  public DomainApplicationCreateFlowCustomLogic forDomainApplicationCreateFlow(
+      EppInput eppInput, SessionMetadata sessionMetadata) {
+    return new TestDomainApplicationCreateFlowCustomLogic(eppInput, sessionMetadata);
+  }
+}