Change snippet import logic from db

changelogs/unreleased/fj-fix-snippet-import-from-database.yml

+---
+title: Fix snippet repository import edge cases
+merge_request: 33506
+author:
+type: fixed

lib/gitlab/import_export/snippet_repo_restorer.rb

@@ -34,14 +34,7 @@ module Gitlab
       end
 
       def create_repository_from_db
-        snippet.create_repository
-
-        commit_attrs = {
-          branch_name: 'master',
-          message: 'Initial commit'
-        }
-
-        repository.create_file(@user, snippet.file_name, snippet.content, commit_attrs)
+        Gitlab::BackgroundMigration::BackfillSnippetRepositories.new.perform_by_ids([snippet.id])
       end
     end
   end

spec/lib/gitlab/import_export/snippet_repo_restorer_spec.rb

@@ -25,10 +25,9 @@ describe Gitlab::ImportExport::SnippetRepoRestorer do
       expect(snippet.repository_exists?).to be_falsey
 
       aggregate_failures do
-        expect(restorer.restore).to be_truthy
-
-        expect(snippet.repository_exists?).to be_truthy
-        expect(snippet.snippet_repository).not_to be_nil
+        expect do
+          expect(restorer.restore).to be_truthy
+        end.to change { SnippetRepository.count }.by(1)
 
         blob = snippet.repository.blob_at('HEAD', snippet.file_name)
         expect(blob).not_to be_nil