encrypt credentials in project_creator for bitbucket by default

lib/gitlab/bitbucket_import/project_creator.rb

@@ -23,7 +23,7 @@ module Gitlab
           import_url: "ssh://git@bitbucket.org/#{repo["owner"]}/#{repo["slug"]}.git",
         ).execute
-        project.create_import_data(data: { "bb_session" => session_data } )
+        project.create_import_data(credentials: { "bb_session" => session_data } )
         project
       end
     end