serverless-sam outputs invalid template for AppRepo

[tmclaugh]

When using serverless-sam to generate a template for AppRepo I get the following error

com.amazonaws.serverlessappsrepo.template.InvalidTemplateException: Resource with name [ThreatStackAwsSnsPublisherLambdaPermission] is invalid. AWS::Lambda::Permission is not a supported Serverless Apps Repository Type.

After I removed that resource I received a similar error:

com.amazonaws.serverlessappsrepo.template.InvalidTemplateException: Resource with name [SnsConfirmSubscriptionIamManagedPolicy] is invalid. AWS::IAM::ManagedPolicy is not a supported Serverless Apps Repository Type.

Original serverless.yml is here: https://github.com/ServerlessOpsIO/threatstack-aws-sns-publisher/blob/master/serverless.yml
SAM template can be found here: https://s3.amazonaws.com/serverlessops-opensource-deploy-dev/threatstack-aws-sns-publisher/b472ba61a2f1d4c5f007a2c3ae03fcdb8b71e44e-72/deploy/sam-template.yml

Are these just limitations of AppRepo or are they invalid SAM resources?