fix: error message when secret access key is invalid on init

[hi1280]

Description of changes

Changed amplify init error message when the AWS secret access key is invalid, from a message saying Forbidden to a helpful message.

Issue #, if available

Fix #13342

Description of how you validated changes

Added unit test for invalid secret access key.
when running amplify-dev init, a new error message will appear as follows.

? Please choose the profile you want to use default
🛑 The request signature we calculated does not match the signature you provided

Resolution: Check your AWS Secret Access Key
Learn more at: https://docs.amplify.aws/cli/project/troubleshooting/

Checklist

• PR description included
• yarn test passes
• Tests are changed or added
• Relevant documentation is changed or added (and PR referenced)
• New AWS SDK calls or CloudFormation actions have been added to relevant test and service IAM policies
• Pull request labels are added

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