[Java] Inconsistent polymorphism in components and responses

Description

Polymorphism works inconsistently between model and API generation (or between components and responses in schema):
Let's say we have base entity Pet and it's children Cat and Dog.
Component Pets that's defined as

    Pets:
      type: array
      items:
        oneOf:
          - $ref: "#/components/schemas/Dog"
          - $ref: "#/components/schemas/Cat"

is correctly treated as ArrayList

However similar definition in responses

         content:
            application/json:
              schema:
                type: array
                items:
                  oneOf:
                    - $ref: "#/components/schemas/Cat"
                    - $ref: "#/components/schemas/Dog"

generates List as a return type. The workaround is to add intermediate container Pets, but I guess the behavior should be consistent in components and responses.

Swagger-codegen version

3.0.13, reproducible on 3.0.14

Swagger declaration file content or url

openapi: "3.0.0"

info:
  version: 1.0.0
  title: Swagger Petstore
  license:
    name: MIT

servers:
  - url: http://petstore.swagger.io/v1

paths:
  /pets:
    get:
      summary: List all pets
      operationId: listPets
      tags:
        - pets
      parameters:
        - name: limit
          in: query
          description: How many items to return at one time (max 100)
          required: false
          schema:
            type: integer
            format: int32
      responses:
        '200':
          description: A paged array of pets
          headers:
            x-next:
              description: A link to the next page of responses
              schema:
                type: string
          content:
            application/json:    
              schema:
                $ref: "#/components/schemas/Pets"
        default:
          description: unexpected error
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/Error"
    post:
      summary: Create a pet
      operationId: createPets
      tags:
        - pets
      responses:
        '201':
          description: Null response
        default:
          description: unexpected error
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/Error"

  /pets2:
    get:
      summary: List all pets
      operationId: listPets
      tags:
        - pets
      parameters:
        - name: limit
          in: query
          description: How many items to return at one time (max 100)
          required: false
          schema:
            type: integer
            format: int32
      responses:
        '200':
          description: A paged array of pets
          headers:
            x-next:
              description: A link to the next page of responses
              schema:
                type: string
          content:
            application/json:
              schema:
                type: array
                items:
                  oneOf:
                    - $ref: "#/components/schemas/Cat"
                    - $ref: "#/components/schemas/Dog"
        default:
          description: unexpected error
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/Error"

  /pets/{petId}:
    get:
      summary: Info for a specific pet
      operationId: showPetById
      tags:
        - pets
      parameters:
        - name: petId
          in: path
          required: true
          description: The id of the pet to retrieve
          schema:
            type: string
      responses:
        '200':
          description: Expected response to a valid request
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/Pet"
        default:
          description: unexpected error
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/Error"

components:
  schemas:
    Pet:
      type: object
      required:
        - id
        - name
        - petType
      properties:
        id:
          type: integer
          format: int64
        name:
          type: string
        tag:
          type: string
        petType:
          type: string

    Dog:
      allOf:
        - $ref: "#/components/schemas/Pet"
        - type: object
          properties:
            barks:
              type: boolean

    Cat:
      allOf:
        - $ref: "#/components/schemas/Pet"
        - type: object
          properties:
            meows:
              type: boolean

    Pets:
      type: array
      items:
        oneOf:
          - $ref: "#/components/schemas/Dog"
          - $ref: "#/components/schemas/Cat"

    Error:
      type: object
      required:
        - code
        - message
      properties:
        code:
          type: integer
          format: int32
        message:
          type: string

Command line used for generation

generate -l java -Dmodels -Dapis -i petstore.yaml

Steps to reproduce

Generate Java code from schema above, in PetsApi.java:
/pets returns Pets (where Pets extends ArrayList)
/pets1 returns List