[AWS::BedrockAgentCore::GatewayTarget] - [Docs] - ApiKeyCredentialProvider CredentialPrefix with wrong description

### Name of the resource

Other

### Resource name

AWS::BedrockAgentCore::GatewayTarget

### Reference Link

https://docs.aws.amazon.com/AWSCloudFormation/latest/TemplateReference/aws-properties-bedrockagentcore-gatewaytarget-apikeycredentialprovider.html

### Details

Currently states

> The API key credential provider for the gateway target.

This does not describe the CredentialPrefix. We are on the ApiKeyCredentialProvider page. **Everything** here is "The API key credential provider for the gateway target".

The property needs a better description.

Open the linked AWS CloudFormation reference page and locate the ApiKeyCredentialProvider section, then inspect the CredentialPrefix property and its current description. Update the description so it explains CredentialPrefix rather than repeating the provider summary, and confirm the rendered documentation accurately reflects the property.

Written by the indexing model from the issue text.