Body of events.APIGatewayProxyRequest for Binary Data

Hi !

We're testing binary data upload to lambda handler in Golang, but found something strange.

From Settings of API Gateway, there is one type *application/octet-stream* to support any binary format. It's using **AWS Lambda proxy integrations**, so that it doesn't need to set **content handling**.

The size local file file is **280432**, once uploaded to lambda Golang handler, the size of **events.APIGatewayProxyRequest::body** becomes **509869**. By printing the data of body which is a string, it _looks_ like binary with \u0000, but the boolean value **events.APIGatewayProxyRequest::IsBase64Encoded** is always still **false**. In contrast, use openssl to encode the local file in base64, the size of output file is only **379755**, much smaller than body.

Is there any extra tips to handle binary data properly ? Thanks in advance.