Gravity Forms entry export doesn't upload to stateless

[ewsopp]

replicate of udx/wp-stateless#717

Related udx/wp-stateless#408

When you use the Gravity Forms entry export UI the generated .csv file does not upload to the stateless bucket. This means that you often get failures if you're using WP Stateless in a kubernetes environment as the generated .csv file is not present on the pod when WordPress tries to download it.