Add Grape content logger to log length and range

This commits adds another Grape logger. ContentLogger is going to long
content-length and content-range if provided.

lib/api/api.rb

@@ -25,7 +25,8 @@ module API
                     Gitlab::GrapeLogging::Loggers::QueueDurationLogger.new,
                     Gitlab::GrapeLogging::Loggers::PerfLogger.new,
                     Gitlab::GrapeLogging::Loggers::CorrelationIdLogger.new,
-                    Gitlab::GrapeLogging::Loggers::ContextLogger.new
+                    Gitlab::GrapeLogging::Loggers::ContextLogger.new,
+                    Gitlab::GrapeLogging::Loggers::ContentLogger.new
                   ]
 
     allow_access_with_scope :api

lib/gitlab/grape_logging/loggers/content_logger.rb

+# frozen_string_literal: true
+
+module Gitlab
+  module GrapeLogging
+    module Loggers
+      class ContentLogger < ::GrapeLogging::Loggers::Base
+        def parameters(request, _)
+          {
+            content_length: request.env['CONTENT_LENGTH'],
+            content_range: request.env['HTTP_CONTENT_RANGE']
+          }.compact
+        end
+      end
+    end
+  end
+end