Camel Rest Binding throws Excepiton to unmarshal a json data into Java object

Issue

This is the part of Rest DSL implementation:

rest("/sample")
 .consumes(MediaType.APPLICATION_JSON.toString())
 .produces(MediaType.APPLICATION_JSON.toString())
 .post("/demo")
 .type(String.class)
 .bindingMode(RestBindingMode.json)
 .outType(String.class)
 .to("direct:demo");

This is the test HTTP request:

curl --location --request POST 'http://localhost:8180/api/sample/demo' \
--header 'Content-Type: text/plain' \
--data-raw 'test'

By somehow, Camel Rest Binding throws Excepiton to unmarshal a json data into Java object.

com.fasterxml.jackson.core.JsonParseException: Unrecognized token 'test': was expecting ('true', 'false' or 'null')
 at [Source: (ByteArrayInputStream); line: 1, column: 35]
 at com.fasterxml.jackson.core.JsonParser._constructError(JsonParser.java:1804) ~[jackson-core-2.9.10.jar:2.9.10]
 at com.fasterxml.jackson.core.base.ParserMinimalBase._reportError(ParserMinimalBase.java:703) ~[jackson-core-2.9.10.jar:2.9.10]
 at com.fasterxml.jackson.core.json.UTF8StreamJsonParser._reportInvalidToken(UTF8StreamJsonParser.java:3532) ~[jackson-core-2.9.10.jar:2.9.10]
 at com.fasterxml.jackson.core.json.UTF8StreamJsonParser._handleUnexpectedValue(UTF8StreamJsonParser.java:2627) ~[jackson-core-2.9.10.jar:2.9.10]
 at com.fasterxml.jackson.core.json.UTF8StreamJsonParser._nextTokenNotInObject(UTF8StreamJsonParser.java:832) ~[jackson-core-2.9.10.jar:2.9.10]
 at com.fasterxml.jackson.core.json.UTF8StreamJsonParser.nextToken(UTF8StreamJsonParser.java:729) ~[jackson-core-2.9.10.jar:2.9.10]
 at com.fasterxml.jackson.databind.ObjectMapper._initForReading(ObjectMapper.java:4142) ~[jackson-databind-2.9.10.4-redhat-00001.jar:2.9.10.4-redhat-00001]       
 at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:4001) ~[jackson-databind-2.9.10.4-redhat-00001.jar:2.9.10.4-redhat-00001]      
 at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3071) ~[jackson-databind-2.9.10.4-redhat-00001.jar:2.9.10.4-redhat-00001]