title: AWS CDK update/add lifecycle to existing S3 bucket using custom source
body: <p>I created an S3 bucket but now I would like to update/add lifecycle policies to it using CDK.
  Currently I can import this bucket to a new stack file.</p>
  <pre><code>const testBucket = s3.Bucket.fromBucketAttributes(this, 'TestBucket', {
              bucketArn: 'arn:aws:s3:::xxxxxx'});
  </code></pre>
  <p>How can I use <code>AwsCustomResource</code> to update/add lifecycle policies? For example, for <code>prefix = long</code>, I want those objects to expire in 7 days, and for <code>prefix = short</code>, I want them to expire in 3 days.</p>
  <p>Or is there a general way of updating an existing S3 bucket in a new stack with CDK?</p>