[BUG] [Kotlin] Wrong default value is generated for non-integer numbers

Created by: aghajani

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• [ x 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?

Description

If the model has fields with

• type number and format float or double
• type integer and format int64 then the generated models for kotlin will have syntax errors. Samples below

openapi-generator version

6.1.1

OpenAPI declaration file content or url

openapi: 3.0.0
info:
  title: 'Issue X default value number with format'
  version: latest
paths:
  '/':
    get:
      operationId: operation
      responses:
        '200':
          description: Success
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ModelWithPropertyHavingDefault'
components:
  schemas:
    ModelWithPropertyHavingDefault:
      properties:
        propertyInt:
          type: integer
          default: 0
          format: int32
        propertyLong:
          type: integer
          default: 0
          format: int64
        propertyFloat1:
          type: number
          default: 0
          format: float
        propertyFloat2:
          type: number
          default: 0.0
          format: float
        propertyFloat3:
          type: number
          default: 0.01
          format: float
        propertyDouble1:
          type: number
          default: 0
          format: double
        propertyDouble2:
          type: number
          default: 0.0
          format: double
        propertyDouble3:
          type: number
          default: 0.01
          format: double

Generation Details

Steps to reproduce

Try to generate kotlin (client) models, and the output will have:

    @SerializedName("propertyLong")
    val propertyLong: kotlin.Long? = 0,

    @SerializedName("propertyFloat1")
    val propertyFloat1: kotlin.Float? = 0,

    @SerializedName("propertyFloat2")
    val propertyFloat2: kotlin.Float? = 0,

    @SerializedName("propertyFloat3")
    val propertyFloat3: kotlin.Float? = 0.01,

    @SerializedName("propertyDouble1")
    val propertyDouble1: kotlin.Double? = 0,

    @SerializedName("propertyDouble2")
    val propertyDouble2: kotlin.Double? = 0,

which is clearly invalid in Kotlin.
Expected output:

    @SerializedName("propertyInt")
    val propertyInt: kotlin.Int? = 0,

    @SerializedName("propertyLong")
    val propertyLong: kotlin.Long? = 0L,

    @SerializedName("propertyFloat1")
    val propertyFloat1: kotlin.Float? = 0f,

    @SerializedName("propertyFloat2")
    val propertyFloat2: kotlin.Float? = 0.0f,

    @SerializedName("propertyFloat3")
    val propertyFloat3: kotlin.Float? = 0.01f,

    @SerializedName("propertyDouble1")
    val propertyDouble1: kotlin.Double? = 0.0,

    @SerializedName("propertyDouble2")
    val propertyDouble2: kotlin.Double? = 0.0,

    @SerializedName("propertyDouble3")
    val propertyDouble3: kotlin.Double? = 0.01

Suggest a fix

The fix should consider the type and shape the output default value (better to be in abstract Kotlin generator)