support overriding auth/unauth role on amplify init

### Is this feature request related to a new or existing Amplify category?

_No response_

### Is this related to another service?

IAM

### Describe the feature you'd like to request

When using amplify init it's failing due to not being able to override the IAM roles for AuthRole and UnAuthRole. I'd like to be able to set custom paths for the auth/unauth roles on init call for specific security requirements.

### Describe the solution you'd like

What done looks like:
amplify init --override roles auth:$customAuthRole unAuth:$customUnAuthRole

### Describe alternatives you've considered

in theory I understand I can use the CLI and use the "override" command option to override the role path and permissions boundary. However, I can only override the role after running "amplify init"

### Additional context

_No response_

### Is this something that you'd be interested in working on?

- [ ] 👋 I may be able to implement this feature request

### Would this feature include a breaking change?

- [ ] ⚠️ This feature might incur a breaking change