Use remote_directory from config for object storage stubs

Currently, the tests rely on the values from config/gitlab.yml
Let's use them directly instead of hard-coding them

spec/support/helpers/stub_object_storage.rb

@@ -4,7 +4,6 @@ module StubObjectStorage
   def stub_dependency_proxy_object_storage(**params)
     stub_object_storage_uploader(config: ::Gitlab.config.dependency_proxy.object_store,
                                   uploader: ::DependencyProxy::FileUploader,
-                                  remote_directory: 'dependency_proxy',
                                   **params)
   end
 
@@ -16,7 +15,6 @@ module StubObjectStorage
   def stub_object_storage_uploader(
     config:,
         uploader:,
-        remote_directory:,
         enabled: true,
         proxy_download: false,
         background_upload: false,
@@ -40,7 +38,7 @@ module StubObjectStorage
     return unless enabled
 
     stub_object_storage(connection_params: uploader.object_store_credentials,
-                        remote_directory: remote_directory)
+                        remote_directory: config.remote_directory)
   end
 
   def stub_object_storage(connection_params:, remote_directory:)
@@ -60,56 +58,48 @@ module StubObjectStorage
   def stub_artifacts_object_storage(uploader = JobArtifactUploader, **params)
     stub_object_storage_uploader(config: Gitlab.config.artifacts.object_store,
                                  uploader: uploader,
-                                 remote_directory: 'artifacts',
                                  **params)
   end
 
   def stub_external_diffs_object_storage(uploader = described_class, **params)
     stub_object_storage_uploader(config: Gitlab.config.external_diffs.object_store,
                                  uploader: uploader,
-                                 remote_directory: 'external-diffs',
                                  **params)
   end
 
   def stub_lfs_object_storage(**params)
     stub_object_storage_uploader(config: Gitlab.config.lfs.object_store,
                                  uploader: LfsObjectUploader,
-                                 remote_directory: 'lfs-objects',
                                  **params)
   end
 
   def stub_package_file_object_storage(**params)
     stub_object_storage_uploader(config: Gitlab.config.packages.object_store,
                                  uploader: ::Packages::PackageFileUploader,
-                                 remote_directory: 'packages',
                                  **params)
   end
 
   def stub_composer_cache_object_storage(**params)
     stub_object_storage_uploader(config: Gitlab.config.packages.object_store,
                                  uploader: ::Packages::Composer::CacheUploader,
-                                 remote_directory: 'packages',
                                  **params)
   end
 
   def stub_uploads_object_storage(uploader = described_class, **params)
     stub_object_storage_uploader(config: Gitlab.config.uploads.object_store,
                                  uploader: uploader,
-                                 remote_directory: 'uploads',
                                  **params)
   end
 
   def stub_terraform_state_object_storage(**params)
     stub_object_storage_uploader(config: Gitlab.config.terraform_state.object_store,
                                  uploader: Terraform::StateUploader,
-                                 remote_directory: 'terraform',
                                  **params)
   end
 
   def stub_pages_object_storage(uploader = described_class, **params)
     stub_object_storage_uploader(config: Gitlab.config.pages.object_store,
                                  uploader: uploader,
-                                 remote_directory: 'pages',
                                  **params)
   end