feat(bedrock): stabilityai model (#29210)

- New URL
- Adding Model
    - stability.stable-diffusion-xl-v0
    - stability.stable-diffusion-xl-v1 

### Checklist
- [x] My code adheres to the [CONTRIBUTING GUIDE](https://github.com/aws/aws-cdk/blob/main/CONTRIBUTING.md) and [DESIGN GUIDELINES](https://github.com/aws/aws-cdk/blob/main/docs/DESIGN_GUIDELINES.md)

----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

packages/aws-cdk-lib/aws-bedrock/lib/foundation-model.ts

@@ -5,7 +5,7 @@ import { ArnFormat, Stack } from '../../core';
 /**
  * The model identifiers for the Bedrock base foundation models.
  *
- * @see https://docs.aws.amazon.com/bedrock/latest/userguide/model-ids-arns.html
+ * @see https://docs.aws.amazon.com/bedrock/latest/userguide/model-ids.html
  */
 export class FoundationModelIdentifier {
   /** Base model "ai21.j2-mid-v1". */
@@ -56,6 +56,12 @@ export class FoundationModelIdentifier {
   /** Base model "meta.llama2-70b-chat-v1". */
   public static readonly META_LLAMA_2_CHAT_70B_V1 = new FoundationModelIdentifier('meta.llama2-70b-chat-v1');
 
+  /** Base model "stability.stable-diffusion-xl-v0". */
+  public static readonly STABILITY_STABLE_DIFFUSION_XL_V0 = new FoundationModelIdentifier('stability.stable-diffusion-xl-v0');
+
+  /** Base model "stability.stable-diffusion-xl-v1". */
+  public static readonly STABILITY_STABLE_DIFFUSION_XL_V1 = new FoundationModelIdentifier('stability.stable-diffusion-xl-v1');
+
   /**
    * Constructor for foundation model identifier
    * @param modelId the model identifier