docs: update s3 bucket physical names to use amazon owned s3 buckets (#31576)

### Issue # (if applicable)

Closes #<issue number here>.

### Reason for this change

By using Amazon owned s3 bucket physical names, we remove the possibility of documenting customer owned buckets in our examples. 

### Description of changes

Change physical S3 bucket names such as `my-bucket` to Amazon owned ones such as `amzn-s3-demo-bucket`. 

### Description of how you validated changes



### 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: evzzk

CHANGELOG.md

@@ -7484,10 +7484,10 @@ const bucket = new s3.Bucket(this, 'L2Bucket');
 const bucketResource = bucket.findChild('Resource') as s3.cloudformation.BucketResource;
 
 // strongly-typed overrides
-bucketResource.propertyOverrides.bucketName = 'NewBucketName';
+bucketResource.propertyOverrides.bucketName = 'amzn-s3-demo-bucket';
 
 // weakly-typed overrides
-bucketResource.addPropertyOverride('BucketName', 'NewerBucketName');
+bucketResource.addPropertyOverride('BucketName', 'amzn-s3-demo-bucket1');
 ```
 
 ### Bug Fixes
@@ -8289,7 +8289,7 @@ new Pipeline(this, 'MyCoolPipeline', { artifactsBucket: bucket });
 You can also import a bucket by just specifying its name:
 
 ```typescript
-const bucket = Bucket.import({ bucketName: new BucketName('my-bucket') });
+const bucket = Bucket.import({ bucketName: new BucketName('amzn-s3-demo-bucket') });
 new Pipeline(this, 'MyCoolPipeline', { artifactsBucket: bucket });
 ```
 

packages/@aws-cdk-testing/framework-integ/test/aws-servicediscovery/test/integ.service-with-http-namespace.lit.js.snapshot/aws-servicediscovery-integ.assets.json

@@ -22,15 +22,15 @@
    "Type": "AWS::ServiceDiscovery::Instance",
    "Properties": {
     "InstanceAttributes": {
-     "arn": "arn:aws:s3:::mybucket"
+     "arn": "arn:aws:s3:::amzn-s3-demo-bucket"
     },
+    "InstanceId": "ervicediscoveryintegMyNamespaceNonIpServiceNonIpInstance45389A2A",
     "ServiceId": {
      "Fn::GetAtt": [
       "MyNamespaceNonIpService3B425009",
       "Id"
      ]
-    },
-    "InstanceId": "ervicediscoveryintegMyNamespaceNonIpServiceNonIpInstance45389A2A"
+    }
    }
   },
   "MyNamespaceIpService220F547F": {
@@ -57,13 +57,13 @@
      "AWS_INSTANCE_IPV4": "54.239.25.192",
      "AWS_INSTANCE_PORT": "80"
     },
+    "InstanceId": "awsservicediscoveryintegMyNamespaceIpServiceIpInstance56070746",
     "ServiceId": {
      "Fn::GetAtt": [
       "MyNamespaceIpService220F547F",
       "Id"
      ]
-    },
-    "InstanceId": "awsservicediscoveryintegMyNamespaceIpServiceIpInstance56070746"
+    }
    }
   }
  },

packages/@aws-cdk-testing/framework-integ/test/aws-servicediscovery/test/integ.service-with-http-namespace.lit.js.snapshot/aws-servicediscovery-integ.template.json

@@ -13,7 +13,7 @@ const service1 = namespace.createService('NonIpService', {
 });
 
 service1.registerNonIpInstance('NonIpInstance', {
-  customAttributes: { arn: 'arn:aws:s3:::mybucket' },
+  customAttributes: { arn: 'arn:aws:s3:::amzn-s3-demo-bucket' },
 });
 
 const service2 = namespace.createService('IpService', {

packages/@aws-cdk-testing/framework-integ/test/aws-servicediscovery/test/integ.service-with-http-namespace.lit.js.snapshot/cdk.out

@@ -336,7 +336,7 @@ class CustomStagingStack extends Stack implements IStagingResources {
 
   public addFile(asset: FileAssetSource): FileStagingLocation {
     return {
-      bucketName: 'myBucket',
+      bucketName: 'amzn-s3-demo-bucket',
       assumeRoleArn: 'myArn',
       dependencyStack: this,
     };

packages/@aws-cdk-testing/framework-integ/test/aws-servicediscovery/test/integ.service-with-http-namespace.lit.js.snapshot/integ.json

@@ -29,7 +29,7 @@ new codestar.GitHubRepository(this, 'GitHubRepo', {
   accessToken: SecretValue.secretsManager('my-github-token', {
     jsonField: 'token',
   }),
-  contentsBucket: s3.Bucket.fromBucketName(this, 'Bucket', 'bucket-name'),
+  contentsBucket: s3.Bucket.fromBucketName(this, 'Bucket', 'amzn-s3-demo-bucket'),
   contentsKey: 'import.zip',
 });
 ```