Changes to Run an instance import

removed the media type application/json for the response with the status 409

added the new push enum value to the request property alert_rules/items/channels/items

media type application/json was changed to a more specific media type application/problem+json for the response status 400

media type application/json was changed to a more specific media type application/problem+json for the response status 401

media type application/json was changed to a more specific media type application/problem+json for the response status 413

media type application/json was changed to a more specific media type application/problem+json for the response status 419

media type application/json was changed to a more specific media type application/problem+json for the response status 423

media type application/json was changed to a more specific media type application/problem+json for the response status 429

media type application/json was changed to a more specific media type application/problem+json for the response status 500