Expose API required by pull-replication plugin

The pull-replication plugin needs to have access to some of the
previusly hidden APIs in order to unit- and integration- test its
functionality.

Change-Id: I4e77d2cc418e623b93ef88887b5f9899263deda5

src/main/java/com/googlesource/gerrit/plugins/replication/FileConfigResource.java

diff --git a/src/main/java/com/googlesource/gerrit/plugins/replication/FileConfigResource.java b/src/main/java/com/googlesource/gerrit/plugins/replication/FileConfigResource.java
index d220b24..e5bd8d0 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/replication/FileConfigResource.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/replication/FileConfigResource.java
@@ -16,6 +16,9 @@
 
 import static com.googlesource.gerrit.plugins.replication.ReplicationQueue.repLog;
 
+import com.google.common.annotations.VisibleForTesting;
+import com.google.gerrit.common.UsedAt;
+import com.google.gerrit.common.UsedAt.Project;
 import com.google.gerrit.server.config.SitePaths;
 import com.google.inject.Inject;
 import java.io.IOException;
@@ -30,7 +33,9 @@
   protected final FileBasedConfig config;
 
   @Inject
-  FileConfigResource(SitePaths site) {
+  @VisibleForTesting
+  @UsedAt(Project.PLUGIN_PULL_REPLICATION)
+  public FileConfigResource(SitePaths site) {
     Path cfgPath = site.etc_dir.resolve(CONFIG_NAME);
     this.config = new FileBasedConfig(cfgPath.toFile(), FS.DETECTED);
     try {

src/main/java/com/googlesource/gerrit/plugins/replication/MergedConfigResource.java

diff --git a/src/main/java/com/googlesource/gerrit/plugins/replication/MergedConfigResource.java b/src/main/java/com/googlesource/gerrit/plugins/replication/MergedConfigResource.java
index 4cd0af0..399096a 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/replication/MergedConfigResource.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/replication/MergedConfigResource.java
@@ -17,6 +17,8 @@
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.flogger.FluentLogger;
 import com.google.gerrit.common.Nullable;
+import com.google.gerrit.common.UsedAt;
+import com.google.gerrit.common.UsedAt.Project;
 import com.google.gerrit.extensions.registration.DynamicItem;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
@@ -26,7 +28,8 @@
 
 public class MergedConfigResource {
   @VisibleForTesting
-  static MergedConfigResource withBaseOnly(ConfigResource base) {
+  @UsedAt(Project.PLUGIN_PULL_REPLICATION)
+  public static MergedConfigResource withBaseOnly(ConfigResource base) {
     return new MergedConfigResource(Providers.of(base), null);
   }