[html2] Example Object is Rendered as "example: [object Object]"

Description

When generating language = html2 with the below example, the response schema gets rendered as:

{
  title: string
  body: string
}
example: [object Object]

But this should be supported per: https://swagger.io/docs/specification/adding-examples/#schemas

Swagger-codegen version

v3.0.14 - v3.0.23

Swagger declaration file content or url

openapi: 3.0.0
info:
  title: example
  version: 0.0.0
paths:
  /example:
    get:
      responses:
        200:
          description: OK
          content:
            application/json:
              schema:
                type: object
                properties:
                  title:
                    type: string
                  body:
                    type: string
                example:
                  title: example title
                  body: example body

Command line used for generation

The Maven plugin: https://mvnrepository.com/artifact/io.swagger.codegen.v3/swagger-codegen-maven-plugin

Steps to reproduce

See above.

Related issues/PRs

Possibly https://github.com/swagger-api/swagger-codegen/issues/4896.

Suggest a fix/enhancement

The example could instead be rendered similar to:

{
  title: string
  body: string
}
example: {
  "title": "example title",
  "body": "example body"
}

Start by reproducing the issue with the html2 generator through the Maven plugin and trace how the response schema's example is rendered. Compare the object example with the existing scalar rendering; done means the generated output shows the example's title and body values instead of [object Object].