fix(iam): override Role.applyRemovalPolicy for customizeRoles (#31652)

### Issue # (if applicable)

Closes #31651 

### Reason for this change



`Role.customizeRoles` throws an Error if there is a construct that calls `applyRemovalPolicy` internally. This means users cannot use with some constructs like `RestApi`.

```
Error: Cannot apply RemovalPolicy: no child or not a CfnResource. Apply the removal policy on the CfnResource directly.
```

This can be reproduced with:

```typescript
const app = new App();
Role.customizeRoles(app);
const stack = new Stack(app, 'Stack');
new RestApi(stack, 'RestApi');
```

Or explicitly:
 
```typescript
const app = new App();
Role.customizeRoles(app);
const stack = new Stack(app, 'Stack');
const role = new Role(stack, 'Role', { assumedBy: new ServicePrincipal('sns.amazonaws.com') });
role.applyRemovalPolicy(RemovalPolicy.DESTROY);
```

### Description of changes



While it might be possible to fix `RestApi`, there could be other constructs within aws-cdk-lib that also call `Role.applyRemovalPolicy`. Moreover, it's nearly impossible to make library users aware of this.

Since `Role` implements the `IResource` interface, it has the responsibility to respond to the `applyRemovalPolicy` call. Therefore, I think it would be good to override `applyRemovalPolicy` in the `Role` class.

### Description of how you validated changes



Fixed the existing unit test to change behavior.

### 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*

packages/@aws-cdk-testing/framework-integ/test/aws-iam/test/integ.customize-roles-restapi.js.snapshot/integ-customize-roles-restapi.template.json

@@ -0,0 +1,144 @@
+{
+ "Resources": {
+  "RestApi0C43BF4B": {
+   "Type": "AWS::ApiGateway::RestApi",
+   "Properties": {
+    "Name": "RestApi"
+   }
+  },
+  "RestApiAccount7C83CF5A": {
+   "Type": "AWS::ApiGateway::Account",
+   "Properties": {
+    "CloudWatchRoleArn": {
+     "Fn::Join": [
+      "",
+      [
+       "arn:",
+       {
+        "Ref": "AWS::Partition"
+       },
+       ":iam::",
+       {
+        "Ref": "AWS::AccountId"
+       },
+       ":role/precreated-role-api"
+      ]
+     ]
+    }
+   },
+   "DependsOn": [
+    "RestApi0C43BF4B"
+   ],
+   "UpdateReplacePolicy": "Retain",
+   "DeletionPolicy": "Retain"
+  },
+  "RestApiDeployment180EC503f7fb2c75a4565f0d9e459f179f2a7481": {
+   "Type": "AWS::ApiGateway::Deployment",
+   "Properties": {
+    "Description": "Automatically created by the RestApi construct",
+    "RestApiId": {
+     "Ref": "RestApi0C43BF4B"
+    }
+   },
+   "DependsOn": [
+    "RestApiGET0F59260B"
+   ]
+  },
+  "RestApiDeploymentStageprod3855DE66": {
+   "Type": "AWS::ApiGateway::Stage",
+   "Properties": {
+    "DeploymentId": {
+     "Ref": "RestApiDeployment180EC503f7fb2c75a4565f0d9e459f179f2a7481"
+    },
+    "RestApiId": {
+     "Ref": "RestApi0C43BF4B"
+    },
+    "StageName": "prod"
+   },
+   "DependsOn": [
+    "RestApiAccount7C83CF5A"
+   ]
+  },
+  "RestApiGET0F59260B": {
+   "Type": "AWS::ApiGateway::Method",
+   "Properties": {
+    "AuthorizationType": "NONE",
+    "HttpMethod": "GET",
+    "Integration": {
+     "Type": "MOCK"
+    },
+    "ResourceId": {
+     "Fn::GetAtt": [
+      "RestApi0C43BF4B",
+      "RootResourceId"
+     ]
+    },
+    "RestApiId": {
+     "Ref": "RestApi0C43BF4B"
+    }
+   }
+  }
+ },
+ "Outputs": {
+  "RestApiEndpoint0551178A": {
+   "Value": {
+    "Fn::Join": [
+     "",
+     [
+      "https://",
+      {
+       "Ref": "RestApi0C43BF4B"
+      },
+      ".execute-api.",
+      {
+       "Ref": "AWS::Region"
+      },
+      ".",
+      {
+       "Ref": "AWS::URLSuffix"
+      },
+      "/",
+      {
+       "Ref": "RestApiDeploymentStageprod3855DE66"
+      },
+      "/"
+     ]
+    ]
+   }
+  }
+ },
+ "Parameters": {
+  "BootstrapVersion": {
+   "Type": "AWS::SSM::Parameter::Value<String>",
+   "Default": "/cdk-bootstrap/hnb659fds/version",
+   "Description": "Version of the CDK Bootstrap resources in this environment, automatically retrieved from SSM Parameter Store. [cdk:skip]"
+  }
+ },
+ "Rules": {
+  "CheckBootstrapVersion": {
+   "Assertions": [
+    {
+     "Assert": {
+      "Fn::Not": [
+       {
+        "Fn::Contains": [
+         [
+          "1",
+          "2",
+          "3",
+          "4",
+          "5"
+         ],
+         {
+          "Ref": "BootstrapVersion"
+         }
+        ]
+       }
+      ]
+     },
+     "AssertDescription": "CDK bootstrap stack version 6 required. Please run 'cdk bootstrap' with a recent version of the CDK CLI."
+    }
+   ]
+  }
+ }
+}