fix(stepfunctions-tasks): stateMachine construct doesn't generate a v…

…alid policy for default StateMachineRole (#31801)

### Issue # (if applicable)

Closes #31714.

### Reason for this change

Currently, the step functions `runEcsTask()` will create an IAM policy. The `Resource` section is an ARN constructed by CDK with wildcard `*` appending at the end. However, CDK should `Ref` the resource directly instead of constructing the ARN, while keeping the revision number.

### Description of changes

The same solution as #31615. However this change needs to behind a feature flag because it could be a breaking change.

### Description of how you validated changes

Integration test. Also checked the synth template.

### Checklist
- [ ] 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)

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