To automatically add SSM paramters referencing existing environment for PR builds.

### Before opening, please confirm:

- [X] I have checked to see if my question is addressed in the [FAQ](https://github.com/aws-amplify/amplify-hosting/blob/master/FAQ.md).
- [X] I have [searched for duplicate or closed issues](https://github.com/aws-amplify/amplify-hosting/issues?q=is%3Aissue+).
- [X] I have read the guide for [submitting questions](https://github.com/aws-amplify/amplify-hosting/blob/master/CONTRIBUTING.md).
- [X] I have removed any sensitive information from my code snippets and submission.

### App Id

NEW_APP

### AWS Region

us-east-1

### Amplify Hosting feature

Web previews

### Is your feature request related to a problem? Please describe:

From version 11 [Amplify CLI is using Parameter Store](https://docs.amplify.aws/cli/reference/ssm-parameter-store/) from AWS Systems Manager for imported categories like Storage or Auth as well as Lambda function environment variables.

For PR builds, as the backend environment name will be randomly generated, it is leading to 2 step process to add SSM parameters manually after the first PR build fails.

**Current workaround**: Using [pre-push](https://docs.amplify.aws/cli/project/command-hooks/) script to create these SSM parameters

### Describe how you'd like this feature to work

To directly have an option when enabling the PR builds to reference particular environment's values and automatically create SSM parameters.

Start with the linked AWS Systems Manager Parameter Store documentation and the repository's FAQ.md and CONTRIBUTING.md, then review how Web previews and PR builds are configured. The requested outcome is an option that references a selected environment and automatically creates the required SSM parameters before the PR build, avoiding the documented pre-push workaround.

Written by the indexing model from the issue text.