Reduce visibility of *CredentialsFactory* classes

The SecureCredentialsFactory and AutoReloadSecureCredentialsFactoryDecorator
factories do not need to be public as they are not intended to be
directly used outside of the replication plugin.

Change-Id: If8e828815eae135ffba1b437e48dee875ccc030d
diff --git a/src/main/java/com/googlesource/gerrit/plugins/replication/AutoReloadSecureCredentialsFactoryDecorator.java b/src/main/java/com/googlesource/gerrit/plugins/replication/AutoReloadSecureCredentialsFactoryDecorator.java
index e9409a6..94fb910 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/replication/AutoReloadSecureCredentialsFactoryDecorator.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/replication/AutoReloadSecureCredentialsFactoryDecorator.java
@@ -26,7 +26,7 @@
 import org.eclipse.jgit.errors.ConfigInvalidException;
 import org.eclipse.jgit.transport.CredentialsProvider;
 
-public class AutoReloadSecureCredentialsFactoryDecorator implements CredentialsFactory {
+class AutoReloadSecureCredentialsFactoryDecorator implements CredentialsFactory {
   private static final FluentLogger logger = FluentLogger.forEnclosingClass();
 
   private final AtomicReference<SecureCredentialsFactory> secureCredentialsFactory;
diff --git a/src/main/java/com/googlesource/gerrit/plugins/replication/SecureCredentialsFactory.java b/src/main/java/com/googlesource/gerrit/plugins/replication/SecureCredentialsFactory.java
index ed15b92..a4bd209 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/replication/SecureCredentialsFactory.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/replication/SecureCredentialsFactory.java
@@ -26,7 +26,7 @@
 import org.eclipse.jgit.util.FS;
 
 /** Looks up a remote's password in secure.config. */
-public class SecureCredentialsFactory implements CredentialsFactory {
+class SecureCredentialsFactory implements CredentialsFactory {
   private final Config config;
 
   @Inject