test(storage): fix copy_configuration script

[lawmicha]

Issue #

Description

This fixes the copy configuration script, which was modified to copy the outputs file. but replaced the previous amplifyconfiguration.json instead of it being an addition

The change that introduced the issue https://github.com/aws-amplify/amplify-swift/pull/3567/files#diff-afbd7f754fa78d6674c0136cafca4f962448f9cea32199a51f5e354694dfb75d

General Checklist

• Added new tests to cover change, if needed
• Build succeeds with all target using Swift Package Manager
• All unit tests pass
• All integration tests pass
• Security oriented best practices and standards are followed (e.g. using input sanitization, principle of least privilege, etc)
• Documentation update for the change if required
• PR title conforms to conventional commit style
• New or updated tests include Given When Then inline code documentation and are named accordingly testThing_condition_expectation()
• If breaking change, documentation/changelog update with migration instructions

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.