This will help identify Sidekiq jobs that invoke excessive number of
filesystem access.
The timing data is stored in `RequestStore`, but this is only active
within the middleware and is not directly accessible to the Sidekiq
logger. However, it is possible for the middleware to modify the job
hash to pass this data along to the logger.
This number was reporting a negative number because `current_time` was
a monotonic counter, not an absolute time.
Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/65748
