Swap sender client on the bulk uploader to use the newly provisioned one

[fzhao99]

Description

RS has asked us to swap out our sender client on the bulk uploader to use a newly provisioned one specific to the UP. This will help with our observability into any UP sends.

Proposed solution

1. Refer to this slack thread for the creds swap that needs to happen.
2. Swap out our configuration for our RS sender client in TestResultUploadService to use the new credentials.
3. Reach out to James to do the appropriate testing to validate that the new creds are working