Remove the old RegistryConfig paradigm entirely

We are now ready to begin configuration using YAML, mediated by ConfigModule.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=143818507

javatests/google/registry/backup/RestoreCommitLogsActionTest.java

@@ -49,7 +49,6 @@ import google.registry.model.ofy.CommitLogMutation;
 import google.registry.testing.AppEngineRule;
 import google.registry.testing.FakeClock;
 import google.registry.testing.FakeSleeper;
-import google.registry.testing.RegistryConfigRule;
 import google.registry.testing.TestObject;
 import google.registry.util.Retrier;
 import java.io.ByteArrayOutputStream;
@@ -80,9 +79,6 @@ public class RestoreCommitLogsActionTest {
       .withDatastore()
       .build();
 
-  @Rule
-  public final RegistryConfigRule configRule = new RegistryConfigRule();
-
   @Before
   public void init() {
     ObjectifyService.register(TestObject.class);