Revert "SOLR-17302: Convert /cluster filestore APIs to JAX-RS (#2470)"

This reverts commit 8c5ae1b.

solr/core/src/java/org/apache/solr/core/CoreContainer.java

@@ -104,9 +104,6 @@
 import org.apache.solr.core.DirectoryFactory.DirContext;
 import org.apache.solr.core.backup.repository.BackupRepository;
 import org.apache.solr.core.backup.repository.BackupRepositoryFactory;
-import org.apache.solr.filestore.ClusterFileStore;
-import org.apache.solr.filestore.DistribFileStore;
-import org.apache.solr.filestore.FileStore;
 import org.apache.solr.filestore.FileStoreAPI;
 import org.apache.solr.handler.ClusterAPI;
 import org.apache.solr.handler.RequestHandlerBase;
@@ -297,9 +294,7 @@ && getZkController().getOverseer() != null
   private volatile ClusterEventProducer clusterEventProducer;
   private DelegatingPlacementPluginFactory placementPluginFactory;
 
-  private DistribFileStore fileStore;
   private FileStoreAPI fileStoreAPI;
-  private ClusterFileStore clusterFileStoreAPI;
   private SolrPackageLoader packageLoader;
 
   private final Set<Path> allowPaths;
@@ -728,8 +723,8 @@ public SolrPackageLoader getPackageLoader() {
     return packageLoader;
   }
 
-  public FileStore getFileStore() {
-    return fileStore;
+  public FileStoreAPI getFileStoreAPI() {
+    return fileStoreAPI;
   }
 
   public SolrCache<?, ?> getCache(String name) {
@@ -861,11 +856,9 @@ private void loadInternal() {
               (PublicKeyHandler) containerHandlers.get(PublicKeyHandler.PATH));
       pkiAuthenticationSecurityBuilder.initializeMetrics(solrMetricsContext, "/authentication/pki");
 
-      fileStore = new DistribFileStore(this);
       fileStoreAPI = new FileStoreAPI(this);
       registerV2ApiIfEnabled(fileStoreAPI.readAPI);
       registerV2ApiIfEnabled(fileStoreAPI.writeAPI);
-      registerV2ApiIfEnabled(ClusterFileStore.class);
 
       packageLoader = new SolrPackageLoader(this);
       registerV2ApiIfEnabled(packageLoader.getPackageAPI().editAPI);
@@ -1157,15 +1150,6 @@ protected void configure() {
                       .in(Singleton.class);
                 }
               })
-          .register(
-              new AbstractBinder() {
-                @Override
-                protected void configure() {
-                  bindFactory(new InjectionFactories.SingletonFactory<>(fileStore))
-                      .to(DistribFileStore.class)
-                      .in(Singleton.class);
-                }
-              })
           .register(
               new AbstractBinder() {
                 @Override