id is being sent through as an integer where in the schema it has been defined as a string.
So your payload should ideally look like this:
{"schema":"iglu:com.snowplowanalytics.snowplow/contexts/jsonschema/1-0-0","data":[{"schema":"iglu:com.google.analytics.enhanced-ecommerce/productFieldObject/jsonschema/1-0-0","data":{"id":"17252","name":"Tablet Apple iPad Wi-Fi + Cellular 128GB (2018)","brand":"apple","category":"Phones & Tablets","price":358.8}}