Add Amazon Bedrock Guardrail Support

### On which framework/platform would you like to see this feature implemented?

React

### Which UI component is this feature-request for?

Other

### Please describe your feature-request in detail.

Amplify AI kit has a conversation with tool use but doesn't have conversation with guardrails. I know they are currently mutually exclusive. Could you implement conversation with guardrails please.

### Please describe a solution you'd like.

_No response_

### We love contributors! Is this something you'd be interested in working on?

- [ ] 👋 I may be able to implement this feature request.
- [ ] ⚠️ This feature might incur a breaking change.

The issue concerns adding Amazon Bedrock Guardrail support to an Amplify AI kit conversation with tool use, but it names no files, tests, or entry points. First determine where conversation and tool-use support is implemented, then define the guardrail interaction and verification criteria with maintainers.

Written by the indexing model from the issue text.