fix(stepfunctions-tasks): allow camelCase for parameters of CallAwsServiceCrossRegion (#30795)

### Issue # (if applicable)
closes #30799

### Reason for this change

I found some AWS services uses camelCase for API parameters, such as [api-gateway](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/api-gateway/command/GetRestApiCommand/) or [bedrock-runtime](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/bedrock-runtime/command/InvokeModelCommand/). However, currently `CallAwsServiceCrossRegion` allows only PascalCase for parameters, and it throws an error if parameters are not in PascalCase.

### Description of changes

Because we do not precisely know which service uses camelCase, this PR just removes the validation logic to allow both camelCase and PascalCase for parameters. This will also reduce maintanance cost in the future.

### Description of how you validated changes

Added a unit test.

### 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*

Author: tmokmss

packages/aws-cdk-lib/aws-stepfunctions-tasks/lib/lambda/call-aws-service-cross-region.ts

@@ -11,7 +11,7 @@ import { CrossRegionAwsSdkSingletonFunction } from '../../../custom-resource-han
  */
 export interface CallAwsServiceCrossRegionProps extends sfn.TaskStateBaseProps {
   /**
-   * The AWS service to call in AWS SDK for JavaScript v3 style.
+   * The AWS service to call in AWS SDK for JavaScript v3 format.
    *
    * @see https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/
    * @example 's3'
@@ -26,9 +26,7 @@ export interface CallAwsServiceCrossRegionProps extends sfn.TaskStateBaseProps {
   readonly action: string;
 
   /**
-   * Parameters for the API action call.
-   *
-   * Use PascalCase for the parameter names.
+   * Parameters for the API action call in AWS SDK for JavaScript v3 format.
    *
    * @default - no parameters
    */
@@ -112,12 +110,6 @@ export class CallAwsServiceCrossRegion extends sfn.TaskStateBase {
     if (!Token.isUnresolved(props.action) && !props.action.startsWith(props.action[0]?.toLowerCase())) {
       throw new Error(`action must be camelCase, got: ${props.action}`);
     }
-    if (props.parameters) {
-      const invalidKeys = Object.keys(props.parameters).filter((key) => !key.startsWith(key[0]?.toUpperCase()));
-      if (invalidKeys.length) {
-        throw new Error(`parameter names must be PascalCase, got: ${invalidKeys.join(', ')}`);
-      }
-    }
 
     // props.service expects a service name in the AWS SDK for JavaScript v3 format.
     // In some services, this format differs from the one used in IAM.

packages/aws-cdk-lib/aws-stepfunctions-tasks/test/lambda/call-aws-service-cross-region.test.ts

@@ -162,6 +162,40 @@ test('with custom IAM action', () => {
   });
 });
 
+test('parameters with camelCase', () => {
+  // WHEN
+  const task = new tasks.CallAwsServiceCrossRegion(stack, 'GetRestApi', {
+    service: 'api-gateway',
+    action: 'getRestApi',
+    parameters: {
+      restApiId: 'id',
+    },
+    region: 'us-east-1',
+    iamResources: ['*'],
+    retryOnServiceExceptions: false,
+  });
+
+  // THEN
+  expect(stack.resolve(task.toStateJson())).toEqual({
+    Type: 'Task',
+    Resource: {
+      'Fn::GetAtt': [
+        'CrossRegionAwsSdk8a0c93f3dbef4b71ac137aaf2048ce7eF7430F4F',
+        'Arn',
+      ],
+    },
+    End: true,
+    Parameters: {
+      action: 'getRestApi',
+      region: 'us-east-1',
+      service: 'api-gateway',
+      parameters: {
+        restApiId: 'id',
+      },
+    },
+  });
+});
+
 test('throws with invalid integration pattern', () => {
   expect(() => new tasks.CallAwsServiceCrossRegion(stack, 'GetObject', {
     integrationPattern: sfn.IntegrationPattern.RUN_JOB,
@@ -189,19 +223,6 @@ test('throws if action is not camelCase', () => {
   })).toThrow(/action must be camelCase, got: GetObject/);
 });
 
-test('throws if parameters has keys as not PascalCase', () => {
-  expect(() => new tasks.CallAwsServiceCrossRegion(stack, 'GetObject', {
-    service: 's3',
-    action: 'getObject',
-    parameters: {
-      bucket: 'my-bucket',
-      key: sfn.JsonPath.stringAt('$.key'),
-    },
-    region: 'us-east-1',
-    iamResources: ['*'],
-  })).toThrow(/parameter names must be PascalCase, got: bucket, key/);
-});
-
 test('can pass additional IAM statements', () => {
   // WHEN
   const task = new tasks.CallAwsServiceCrossRegion(stack, 'DetectLabels', {