Merge changes from topic 'checkstyle-cleanup'

* changes:
  Remove redundant modifiers from interfaces' methods
  Remove redundant 'final' modifier from private native methods
  Checkstyle config: Enable "redundant modifier" and "redundant import"

gerrit-server/src/main/java/com/google/gerrit/server/account/EmailExpander.java

@@ -23,7 +23,7 @@ public interface EmailExpander {
 
   String expand(String user);
 
-  public static class None implements EmailExpander {
+  class None implements EmailExpander {
     public static final None INSTANCE = new None();
 
     public static boolean canHandle(final String fmt) {
@@ -44,7 +44,7 @@ public interface EmailExpander {
     }
   }
 
-  public static class Simple implements EmailExpander {
+  class Simple implements EmailExpander {
     private static final String PLACEHOLDER = "{0}";
 
     public static boolean canHandle(final String fmt) {

gerrit-server/src/main/java/com/google/gerrit/server/account/GroupMembership.java

@@ -24,7 +24,7 @@ import java.util.Set;
  * the presence of a user in a particular group.
  */
 public interface GroupMembership {
-  public static final GroupMembership EMPTY =
+  GroupMembership EMPTY =
       new ListGroupMembership(Collections.<AccountGroup.UUID>emptySet());
 
   /**

gerrit-server/src/main/java/com/google/gerrit/server/api/accounts/AccountExternalIdCreator.java

@@ -32,6 +32,6 @@ public interface AccountExternalIdCreator {
    *
    * @return a list of external identifiers, or an empty list.
    */
-  public List<AccountExternalId> create(Account.Id id, String username,
+  List<AccountExternalId> create(Account.Id id, String username,
       String email);
 }

gerrit-server/src/main/java/com/google/gerrit/server/cache/PersistentCache.java

@@ -18,7 +18,7 @@ public interface PersistentCache {
 
   DiskStats diskStats();
 
-  public static class DiskStats {
+  class DiskStats {
     private final long size;
     private final long space;
     private final long hitCount;

gerrit-server/src/main/java/com/google/gerrit/server/change/MergeabilityCache.java

@@ -23,7 +23,7 @@ import org.eclipse.jgit.lib.Repository;
 
 /** Cache for mergeability of commits into destination branches. */
 public interface MergeabilityCache {
-  public static class NotImplemented implements MergeabilityCache {
+  class NotImplemented implements MergeabilityCache {
     @Override
     public boolean get(ObjectId commit, Ref intoRef, SubmitType submitType,
         String mergeStrategy, Branch.NameKey dest, Repository repo) {

gerrit-server/src/main/java/com/google/gerrit/server/git/QueueProvider.java

@@ -15,7 +15,7 @@
 package com.google.gerrit.server.git;
 
 public interface QueueProvider {
-  public static enum QueueType {
+  enum QueueType {
     INTERACTIVE, BATCH
   }
 

gerrit-server/src/main/java/com/google/gerrit/server/mail/EmailTokenVerifier.java

@@ -39,7 +39,7 @@ public interface EmailTokenVerifier {
   ParsedToken decode(String tokenString) throws InvalidTokenException;
 
   /** Exception thrown when a token does not parse correctly. */
-  public static class InvalidTokenException extends Exception {
+  class InvalidTokenException extends Exception {
     private static final long serialVersionUID = 1L;
 
     public InvalidTokenException() {
@@ -52,7 +52,7 @@ public interface EmailTokenVerifier {
   }
 
   /** Pair returned from decode to provide the data used during encode. */
-  public static class ParsedToken {
+  class ParsedToken {
     private final Account.Id accountId;
     private final String emailAddress;
 

gerrit-server/src/main/java/com/google/gerrit/server/plugins/PluginContentScanner.java

@@ -74,7 +74,7 @@ public interface PluginContentScanner {
    * provided by a plugin to extend an existing
    * extension point in Gerrit.
    */
-  public static class ExtensionMetaData {
+  class ExtensionMetaData {
     public final String className;
     public final String annotationValue;
 

gerrit-server/src/main/java/com/google/gerrit/server/plugins/ServerPluginProvider.java

@@ -37,7 +37,7 @@ public interface ServerPluginProvider {
   /**
    * Descriptor of the Plugin that ServerPluginProvider has to load.
    */
-  public class PluginDescription {
+  class PluginDescription {
     public final PluginUser user;
     public final String canonicalUrl;
     public final Path dataDir;

gerrit-server/src/main/java/com/google/gerrit/server/validators/OutgoingEmailValidationListener.java

@@ -29,7 +29,7 @@ public interface OutgoingEmailValidationListener {
   /**
    * Arguments supplied to validateOutgoingEmail.
    */
-  public static class Args {
+  class Args {
     // in arguments
     public String messageClass;