Clean up some code quality issues

This removes some qualifiers that aren't necessary (e.g. public/abstract on interfaces, private on enum constructors, final on private methods, static on nested interfaces/enums), uses Java 8 lambdas and features where that's an improvement

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=177182945

javatests/google/registry/testing/AppEngineRule.java

@@ -298,12 +298,7 @@ public final class AppEngineRule extends ExternalResource {
     }
 
     if (clock != null) {
-      helper.setClock(new com.google.appengine.tools.development.Clock() {
-        @Override
-        public long getCurrentTime() {
-          return clock.nowUtc().getMillis();
-        }
-      });
+      helper.setClock(() -> clock.nowUtc().getMillis());
     }
 
     if (withLocalModules) {

javatests/google/registry/testing/DatastoreHelper.java

@@ -56,7 +56,6 @@ import com.google.common.collect.Streams;
 import com.google.common.net.InetAddresses;
 import com.googlecode.objectify.Key;
 import com.googlecode.objectify.VoidWork;
-import com.googlecode.objectify.Work;
 import com.googlecode.objectify.cmd.Saver;
 import google.registry.dns.writer.VoidDnsWriter;
 import google.registry.model.Buildable;
@@ -1030,11 +1029,7 @@ public class DatastoreHelper {
 
   /** Force the create and update timestamps to get written into the resource. **/
   public static <R> R cloneAndSetAutoTimestamps(final R resource) {
-    return ofy().transact(new Work<R>() {
-      @Override
-      public R run() {
-        return ofy().load().fromEntity(ofy().save().toEntity(resource));
-      }});
+    return ofy().transact(() -> ofy().load().fromEntity(ofy().save().toEntity(resource)));
   }
 
   /** Returns the entire map of {@link PremiumListEntry}s for the given {@link PremiumList}. */

javatests/google/registry/testing/DeterministicStringGenerator.java

@@ -60,16 +60,16 @@ public class DeterministicStringGenerator extends StringGenerator {
   @Override
   public String createString(int length) {
     checkArgument(length > 0, "String length must be positive.");
-    String password = "";
+    StringBuilder password = new StringBuilder();
     for (int i = 0; i < length; i++) {
-      password += iterator.next();
+      password.append(iterator.next());
     }
     switch (rule) {
       case PREPEND_COUNTER:
-        return String.format("%04d_%s", counter++, password);
+        return String.format("%04d_%s", counter++, password.toString());
       case DEFAULT:
       default:
-        return password;
+        return password.toString();
     }
   }
 

javatests/google/registry/testing/FakeKeyringModule.java

@@ -76,8 +76,6 @@ public final class FakeKeyringModule {
         PgpHelper.lookupKeyPair(publics, privates, SIGNING_KEY_EMAIL, SIGN);
     final PGPPublicKey rdeReceiverKey =
         PgpHelper.lookupPublicKey(publics, RECEIVER_KEY_EMAIL, ENCRYPT);
-    final PGPKeyPair brdaSigningKey = rdeSigningKey;
-    final PGPPublicKey brdaReceiverKey = rdeReceiverKey;
     final String sshPublic =
         readResourceUtf8(FakeKeyringModule.class, "testdata/registry-unittest.id_rsa.pub");
     final String sshPrivate =
@@ -141,12 +139,12 @@ public final class FakeKeyringModule {
 
       @Override
       public PGPKeyPair getBrdaSigningKey() {
-        return brdaSigningKey;
+        return rdeSigningKey;
       }
 
       @Override
       public PGPPublicKey getBrdaReceiverKey() {
-        return brdaReceiverKey;
+        return rdeReceiverKey;
       }
 
       @Override

javatests/google/registry/testing/FullFieldsTestEntityHelper.java

@@ -56,7 +56,7 @@ public final class FullFieldsTestEntityHelper {
 
   public static Registrar makeRegistrar(
       String clientId, String registrarName, Registrar.State state, Long ianaIdentifier) {
-    Registrar registrar = new Registrar.Builder()
+    return new Registrar.Builder()
       .setClientId(clientId)
       .setRegistrarName(registrarName)
       .setType(Registrar.Type.REAL)
@@ -82,7 +82,6 @@ public final class FullFieldsTestEntityHelper {
       .setWhoisServer("whois.example.com")
       .setReferralUrl("http://www.example.com")
       .build();
-    return registrar;
   }
 
   public static ImmutableList<RegistrarContact> makeRegistrarContacts(Registrar registrar) {

javatests/google/registry/testing/Lazies.java

@@ -23,10 +23,6 @@ public final class Lazies {
    * Returns a {@link Lazy} that supplies a constant value.
    */
   public static <T> Lazy<T> of(final T instance) {
-    return new Lazy<T>() {
-      @Override
-      public T get() {
-        return instance;
-      }};
+    return () -> instance;
   }
 }

javatests/google/registry/testing/Providers.java

@@ -24,10 +24,6 @@ public final class Providers {
    *
    */
   public static <T> Provider<T> of(final T instance) {
-    return new Provider<T>() {
-      @Override
-      public T get() {
-        return instance;
-      }};
+    return () -> instance;
   }
 }