IAM: better support for managed policies #621
Description
role.attachManagedPolicy() has a poor signature. It accepts any, but in fact it should accept only Arns (until we have modeled ManagedPolicies)
We had a user try to put a PolicyStatement in there, which led to the following error:
Exception in thread "main" software.amazon.jsii.JsiiException: While synthesizing hello-cdk/source-import-queue-reader/Resource: Trying to resolve() a Construct at /managedPolicyArns/0/Resource�
While synthesizing hello-cdk/source-import-queue-reader/Resource: Trying to resolve() a Construct at /managedPolicyArns/0/Resource�