Add default implementation for the global-refdb logger

Allow using the global-refdb directly without having to
deal with the internals of the loggers implementation by
having a default implementation annotation.

Change-Id: Ic16b1883bbd3f819eed5606a976d2cc2f75e8076
diff --git a/src/main/java/com/gerritforge/gerrit/globalrefdb/validation/SharedRefLogger.java b/src/main/java/com/gerritforge/gerrit/globalrefdb/validation/SharedRefLogger.java
index d2b1822..858ba18 100644
--- a/src/main/java/com/gerritforge/gerrit/globalrefdb/validation/SharedRefLogger.java
+++ b/src/main/java/com/gerritforge/gerrit/globalrefdb/validation/SharedRefLogger.java
@@ -14,9 +14,11 @@
 
 package com.gerritforge.gerrit.globalrefdb.validation;
 
+import com.google.inject.ImplementedBy;
 import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.Ref;
 
+@ImplementedBy(Log4jSharedRefLogger.class)
 public interface SharedRefLogger {
 
   /**