Literals in JSON text body are invalid

For some reason, this is okay (notice the `prefer_sms` field):

```json
{"cookies": [], "postData": {"mimeType": "application/json", "text": "{\"foo\": \"bar\", \"name\": \"Will Gates\", \"prefer_sms\": \"false\"}"}, "url": "http://mockbin.com/request", "queryString": [], "headers": [{"name": "Accept", "value": "application/json"}, {"name": "Content-Type", "value": "application/json"}], "method": "POST", "httpVersion": "HTTP/1.1"}
```

But this isn't:

```json
{"cookies": [], "postData": {"mimeType": "application/json", "text": "{\"foo\": \"bar\", \"name\": \"Will Gates\", \"prefer_sms\": false}"}, "url": "http://mockbin.com/request", "queryString": [], "headers": [{"name": "Accept", "value": "application/json"}, {"name": "Content-Type", "value": "application/json"}], "method": "POST", "httpVersion": "HTTP/1.1"}
```

Even though both are valid JSON. Not sure what to do about this.

Reproduce the issue using the two JSON request examples in the report, comparing the quoted and boolean values in postData.text. Trace the request-body handling entry point that rejects the boolean literal, then consider the issue done when both valid JSON bodies are accepted without changing their value types.

Written by the indexing model from the issue text.