Fix api_json.log not always reporting the right HTTP status code

As described in https://github.com/aserafin/grape_logging/issues/45, if
a Grape error is caught by the handlers and a different return code
is returned, then the api_json.log would have a 500 error code
instead of the right value. Inserting the GrapeLogging middleware
after the Grape middleware fixes this problem.

Seen in https://gitlab.com/gitlab-com/infrastructure/issues/4249

changelogs/unreleased/sh-fix-grape-logging-status-code.yml

+---
+title: Fix api_json.log not always reporting the right HTTP status code
+merge_request:
+author:
+type: fixed

lib/api/api.rb

@@ -8,7 +8,8 @@ module API
     PROJECT_ENDPOINT_REQUIREMENTS = { id: NO_SLASH_URL_PART_REGEX }.freeze
     COMMIT_ENDPOINT_REQUIREMENTS = PROJECT_ENDPOINT_REQUIREMENTS.merge(sha: NO_SLASH_URL_PART_REGEX).freeze
 
-    use GrapeLogging::Middleware::RequestLogger,
+    insert_before Grape::Middleware::Error,
+                  GrapeLogging::Middleware::RequestLogger,
                   logger: Logger.new(LOG_FILENAME),
                   formatter: Gitlab::GrapeLogging::Formatters::LogrageWithTimestamp.new,
                   include: [