[AP] Reverse proxy dev environment update to dev next bucket

[mreed101]

Description

As we prepare for next-build we need to modify all environments to point to their respective s3 buckets.
The goal of this ticket is to update the next_content_proxy_url: to point to http://next-content.dev.va.gov.s3-website-us-gov-west-1.amazonaws.com

Acceptance Criteria

• Reverse proxy dev points to the next-build development bucket
• All test are followed according to the test plan