deafultValue not added to POJO schema in spring-boot generator

Description

When using the spring generator, the @Schema annotation is missing the "defaultValue" parameter for properties that define a default in the openapi YAML file.

openapi-generator version

7.1.0

OpenAPI declaration file content or url

openapi: '3.0.3'
info:
  title: blah blah blan
  version: '1.0'
components:
  schemas:
    Options:
      type: object
      properties:
        xxx:
          type: boolean
          default: false
          description: this is xxx

Generates:

@Schema(name = "xxx", description = "this is xxx", requiredMode = Schema.RequiredMode.NOT_REQUIRED)
  @JsonProperty("xxx")
  public Boolean getXxx() {
    return xxx;
  }

Should generate:

@Schema(name = "xxx", description = "this is xxx", requiredMode = Schema.RequiredMode.NOT_REQUIRED, defaultValue = "false")
  @JsonProperty("xxx")
  public Boolean getXxx() {
    return xxx;
  }

Command line used for generation

Using maven plugin, but can be reproduced with:

java -jar ~/git/openapi-generator/modules/openapi-generator-cli/target/openapi-generator-cli.jar generate -g spring -i openapi.yaml

Suggest a fix/enhancement

I think the resources/JavaSpring/pojo.mustache file needs something like this:
Current:

{{#swagger2AnnotationLibrary}}
  @Schema(name = "{{{baseName}}}"{{#isReadOnly}}, accessMode = Schema.AccessMode.READ_ONLY{{/isReadOnly}}{{#example}}, example = "{{{.}}}"{{/example}}{{#description}}, description = "{{{.}}}"{{/description}}{{#deprecated}}, deprecated = true{{/deprecated}}, requiredMode = {{#required}}Schema.RequiredMode.REQUIRED{{/required}}{{^required}}Schema.RequiredMode.NOT_REQUIRED{{/required}})
  {{/swagger2AnnotationLibrary}}

New:

{{#swagger2AnnotationLibrary}}
  @Schema(name = "{{{baseName}}}"{{#isReadOnly}}, accessMode = Schema.AccessMode.READ_ONLY{{/isReadOnly}}{{#example}}, example = "{{{.}}}"{{/example}}{{#description}}, description = "{{{.}}}"{{/description}}{{#deprecated}}, deprecated = true{{/deprecated}}, requiredMode = {{#required}}Schema.RequiredMode.REQUIRED{{/required}}{{^required}}Schema.RequiredMode.NOT_REQUIRED{{/required}}{{#defaultValue}}, defaultValue = "{{{.}}}"{{/defaultValue}})
  {{/swagger2AnnotationLibrary}}

This same change likely needs to be done anywhere the @Schema is generated for swagger2.

When I tried this locally, it worked for simple properties, but for objects, it added 'defaultValue = "new ArrayList<>()"' instead.

Since I was not sure what other implications this might have, I did not want to suggest via a PR. I'll leave that to someone with more experience.

Reproduce the issue with the supplied OpenAPI YAML and generation command, then inspect resources/JavaSpring/pojo.mustache and the other swagger2 @Schema generation locations. Compare simple and object properties with defaults; done means generated annotations include the correct defaultValue without using generated object expressions such as new ArrayList<>().