Readonly properties are skipped if they are in definitions path

We have read-only properties in the definitions block of the Cloudformation schema [link](https://github.com/mongodb/mongodbatlas-cloudformation-resources/blob/e632a67d7693141009a60108bcda94843a67edcf/cfn-resources/alert-configuration/mongodb-atlas-alertconfiguration.json#L960)

From the code, it seems, we are only considering the read-only attributes from the properties path and skipping them if they are in the definitions path [link](https://github.com/cdklabs/cdk-import/blob/3c0b7f039df581eb3e236bf0dd3f658793cad9ec/src/cfn-resource-generator.ts#L40).