404 redirects appending /index.html

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- [X] I have checked to see if my question is addressed in the [FAQ](https://github.com/aws-amplify/amplify-console/blob/master/FAQ.md).
- [X] I have [searched for duplicate or closed issues](https://github.com/aws-amplify/amplify-console/issues?q=is%3Aissue+).
- [X] I have read the guide for [submitting bug reports](https://github.com/aws-amplify/amplify-console/blob/master/CONTRIBUTING.md).
- [X] I have done my best to include a minimal, self-contained set of instructions for consistently reproducing the issue.

### App Id

_No response_

### Region

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### Amplify Console feature

_No response_

### Describe the bug

Description of the issue:
Setup:
[suba.domain.com](http://suba.domain.com/) - amplify react application
[subb.domain.com](http://subb.domain.com/) - application hosted on EC2

Replication:
With below 404 redirect rule we are trying to redirect to a resource path/page "test" from suba to subb in case the "test" is not present in [suba.domain.com](http://suba.domain.com/).

Source address*: /<\*>
Target address*: [subb.domain.com/](http://subb.domain.com/)<\*>
Type*: 404 redirect
For a "/test" page we are redirected to [subb.domain.com/test/index.html](http://subb.domain.com/test/index.html), however expected behaviour should be "[subb.domain.com/test](http://subb.domain.com/test)"

On using below 301 permanent redirect, the redirections works as expected from [suba.domain.com/test](http://suba.domain.com/test), to [subb.domain.com/test/](http://subb.domain.com/test/),

Source address*: /test
Target address*: [subb.domain.com/test](http://subb.domain.com/test)
Type*: 301 permanent redirect

But use-case requirement is to be it working the same for 404 redirects.

### Expected behavior

For a "/test" page we are redirected to [subb.domain.com/test/index.html](http://subb.domain.com/test/index.html), however expected behaviour should be "[subb.domain.com/test](http://subb.domain.com/test)"

### Reproduction steps

Source address*: /<\*>
Target address*: [subb.domain.com/](http://subb.domain.com/)<\*>
Type*: 404 redirect
For a "/test" page we are redirected to [subb.domain.com/test/index.html](http://subb.domain.com/test/index.html), however expected behaviour should be "[subb.domain.com/test](http://subb.domain.com/test)"

### Build Settings

_No response_

### Additional information

_No response_

Start by reproducing the 404 redirect using the documented Source address /<*> and Target address subb.domain.com/<*> setup, comparing it with the working 301 rule. Done means a request for /test redirects to subb.domain.com/test rather than appending /index.html; the payload names no repository files or tests to inspect.

Written by the indexing model from the issue text.