chore(s3): add auto-generated description to custom resource provider…

… for better recognition of the s3 auto-delete lambda functions in AWS console (#13277)

When having a huge amount of lambda functions it's always nice to have a populated description for better determining the "prurpose-at-a-glance" of what this function is doing (in case you cannot deduce that information from lambda's name).

Depends on #13275. 

----

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

packages/@aws-cdk/aws-s3/lib/bucket.ts

@@ -1830,6 +1830,7 @@ export class Bucket extends BucketBase {
     const provider = CustomResourceProvider.getOrCreateProvider(this, AUTO_DELETE_OBJECTS_RESOURCE_TYPE, {
       codeDirectory: path.join(__dirname, 'auto-delete-objects-handler'),
       runtime: CustomResourceProviderRuntime.NODEJS_12,
+      description: `Lambda function for auto-deleting objects in ${this.bucketName} S3 bucket.`,
     });
 
     // Use a bucket policy to allow the custom resource to delete

packages/@aws-cdk/aws-s3/test/integ.bucket-auto-delete-objects.expected.json

@@ -148,7 +148,19 @@
             "Arn"
           ]
         },
-        "Runtime": "nodejs12.x"
+        "Runtime": "nodejs12.x",
+        "Description": {
+          "Fn::Join": [
+            "",
+            [
+              "Lambda function for auto-deleting objects in ",
+              {
+                "Ref": "Bucket83908E77"
+              },
+              " S3 bucket."
+            ]
+          ]
+        }
       },
       "DependsOn": [
         "CustomS3AutoDeleteObjectsCustomResourceProviderRole3B1BD092"