(aws-cloudfront): Lambda at Edge Cloudwatch log groups retention

When creating a new lambda at edge, the retention policy is ignored for all the regional loggroups created causing the loggroups to never expire

### Reproduction Steps

1. Create a lambda function:

```
const originRequestFunction = new Function(this, 'originRequestFunction', {
...
logRetention: RetentionDays.TWO_WEEKS,
});
```

2. Associate the lambda function to cloudfront:

```
lambdaFunctionAssociations: [
{
eventType: LambdaEdgeEventType.ORIGIN_REQUEST,
lambdaFunction: Version.fromVersionArn(
this,
....
}
]
```

### What did you expect to happen?

The regional loggroups (regional-cache) should follow the retention period specified in the lambda function definition

### What actually happened?

The regional loggroups don't have any expiration

### Environment

- **CDK CLI Version :** 1.60
- **Framework Version:** 1.60
- **Node.js Version:** 12.x
- **OS :** AmazonLinux
- **Language (Version):** TypeScript

---

This is :bug: Bug Report

Start by reproducing the TypeScript Lambda@Edge example with logRetention set to two weeks, then trace the aws-cloudfront Lambda@Edge association and its regional log-group handling. Done means the regional-cache log groups created for the edge function receive the retention period specified on the function.

Written by the indexing model from the issue text.