Remove backendRegistry as api dependency

Signed-off-by: Craig Perkins <cwperx@amazon.com>

Author: cwperks

src/main/java/org/opensearch/security/OpenSearchSecurityPlugin.java

@@ -631,8 +631,7 @@ public List<RestHandler> getRestHandlers(
                         Objects.requireNonNull(auditLog),
                         sks,
                         Objects.requireNonNull(userService),
-                        sslCertReloadEnabled,
-                        backendRegistry
+                        sslCertReloadEnabled
                     )
                 );
                 log.debug("Added {} rest handler(s)", handlers.size());

src/main/java/org/opensearch/security/dlic/rest/api/SecurityApiDependencies.java

@@ -13,7 +13,6 @@
 
 import org.opensearch.common.settings.Settings;
 import org.opensearch.security.auditlog.AuditLog;
-import org.opensearch.security.auth.BackendRegistry;
 import org.opensearch.security.configuration.AdminDNs;
 import org.opensearch.security.configuration.ConfigurationRepository;
 import org.opensearch.security.privileges.PrivilegesEvaluator;
@@ -24,7 +23,6 @@ public class SecurityApiDependencies {
     private final ConfigurationRepository configurationRepository;
     private final RestApiPrivilegesEvaluator restApiPrivilegesEvaluator;
     private final RestApiAdminPrivilegesEvaluator restApiAdminPrivilegesEvaluator;
-    private final BackendRegistry backendRegistry;
     private final AuditLog auditLog;
     private final Settings settings;
 
@@ -37,8 +35,7 @@ public SecurityApiDependencies(
         final RestApiPrivilegesEvaluator restApiPrivilegesEvaluator,
         final RestApiAdminPrivilegesEvaluator restApiAdminPrivilegesEvaluator,
         final AuditLog auditLog,
-        final Settings settings,
-        final BackendRegistry backendRegistry
+        final Settings settings
     ) {
         this.adminDNs = adminDNs;
         this.configurationRepository = configurationRepository;
@@ -47,7 +44,6 @@ public SecurityApiDependencies(
         this.restApiAdminPrivilegesEvaluator = restApiAdminPrivilegesEvaluator;
         this.auditLog = auditLog;
         this.settings = settings;
-        this.backendRegistry = backendRegistry;
     }
 
     public AdminDNs adminDNs() {
@@ -78,10 +74,6 @@ public Settings settings() {
         return settings;
     }
 
-    public BackendRegistry backendRegistry() {
-        return backendRegistry;
-    }
-
     public String securityIndexName() {
         return settings().get(ConfigConstants.SECURITY_CONFIG_INDEX_NAME, ConfigConstants.OPENDISTRO_SECURITY_DEFAULT_CONFIG_INDEX);
     }

src/main/java/org/opensearch/security/dlic/rest/api/SecurityRestApiActions.java

@@ -21,7 +21,6 @@
 import org.opensearch.rest.RestController;
 import org.opensearch.rest.RestHandler;
 import org.opensearch.security.auditlog.AuditLog;
-import org.opensearch.security.auth.BackendRegistry;
 import org.opensearch.security.configuration.AdminDNs;
 import org.opensearch.security.configuration.ConfigurationRepository;
 import org.opensearch.security.privileges.PrivilegesEvaluator;
@@ -48,8 +47,7 @@ public static Collection<RestHandler> getHandler(
         final AuditLog auditLog,
         final SecurityKeyStore securityKeyStore,
         final UserService userService,
-        final boolean certificatesReloadEnabled,
-        final BackendRegistry backendRegistry
+        final boolean certificatesReloadEnabled
     ) {
         final var securityApiDependencies = new SecurityApiDependencies(
             adminDns,
@@ -63,8 +61,7 @@ public static Collection<RestHandler> getHandler(
                 settings.getAsBoolean(SECURITY_RESTAPI_ADMIN_ENABLED, false)
             ),
             auditLog,
-            settings,
-            backendRegistry
+            settings
         );
         return List.of(
             new InternalUsersApiAction(clusterService, threadPool, userService, securityApiDependencies),