Object created that ends with something, e.g. .fla.json:

{
  "detail": {
    "bucket": {
      "name": ["tetra-config-bucket-test-1234"]
    },
    "object": {
      "key": [{
        "suffix": ".fla.json"
      }]
    }
  },
  "detail-type": ["Object Created"],
  "source": ["aws.s3"]
}