[BUG] Kotlin-retrofit2-gson-coroutines CollectionsFormat.CSVParams default value is set to arrayListOf()

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• Have you tested with the latest master to confirm the issue still exists?
• Have you searched for related issues/PRs?
• What's the actual output vs expected output?
• [Optional] Sponsorship to speed up the bug fix or feature request (example)

Description

Open api generator where the code generated gives parameter of type CSVParams gives wrong default implementation, it should create the CSVParams class but instead it is @Query("sort") sort: CSVParams? = arrayListOf("date:desc")

openapi-generator version

7.6.0

OpenAPI declaration file content or url

    SortSchema:
      type: array
      description: |
        ...
      default: [ 'date:desc' ]
      items:
        type: string
        pattern: '^(date|name|popularity|trend)(:(asc|desc))?$'
      example: [ 'date:desc', 'name' ]

Generation Details

        generatorName = "kotlin"
        inputSpec = "$rootDir/data/src/main/assets/openapi/${spec.value}"
        outputDir = "$buildDir/generated/openapi"
        configOptions = [
                dateLibrary         : "java17",
                library             : "jvm-retrofit2",
                serializationLibrary: "gson",
                useCoroutines       : "true"
        ]
        nameMappings = [
                "identifier": "id"
        ]
        modelNamePrefix = "Api"
        apiNameSuffix = "Api"
        generateModelTests = false
        generateApiTests = false

Steps to reproduce

• Generate retrofit API and classes with openApiGenerate {}
• Build fails due to compilation error

Related issues/PRs

Suggest a fix

Default value of CSVParams should create an instance of CSVParams class instead of ArrayList

Start with the provided OpenAPI declaration and generation settings, then run openApiGenerate for the Kotlin jvm-retrofit2 client with Gson and coroutines. Inspect the generated declaration for the CSVParams parameter and compare its default value with the expected CSVParams instance. Done means the generated client compiles and uses the appropriate default type.