[Java] null property serialization in non-dynamic-property value

[vmatyus]

Now I am writing about an issue in Cloudant Java SDK. I updated the java package in our Gauge automated test and the execution detected a deviation in the Java SDK.
In one of the Request Bodys there is a field (source) that defines the route to a database and its authentication. This field received a new auth: null and header: null fields.
When the auth object not defined:

"source": {
    "auth": null,
    "headers": {
      "Authorization": "basic 1234567"
    },
    "url": "${CLOUDANT_URL}/dbname"
  },

When the header is not defined:

"source": {
    "auth": {
        "iam": {
            "api_key": "<api_key>"
        }
    },
    "headers": null,
    "url": "${CLOUDANT_URL}/dbname"
  }

For this request the server answers:

403 Forbidden
{
    "error": "forbidden",
    "reason": "`source.headers' must be a non-null object."
}

I suspect this operation change introduced in this correction: #82
auth component is not a dynamic-property, so this field should not be serialized.
Does headers count to be a dynamic-property value?

Here is the definition of the problematic component:

ReplicationDatabase:
      additionalProperties: false
      description: Schema for a replication source or target database.
      properties:
        auth:
          $ref: '#/components/schemas/ReplicationDatabaseAuth'
        headers:
          additionalProperties:
            type: string
          description: Replication request headers.
          type: object
        url:
          description: Replication database URL.
          type: string
      type: object
ReplicationDatabaseAuth:
      additionalProperties: false
      description: Schema for replication source or target database authentication.
      properties:
        iam:
          $ref: '#/components/schemas/ReplicationDatabaseAuthIam'
      type: object
ReplicationDatabaseAuthIam:
      additionalProperties: false
      description: Schema for an IAM API key for replication database authentication.
      properties:
        api_key:
          description: IAM API key.
          type: string
      type: object

[vmatyus]

Moved to an other repo: https://github.ibm.com/arf/planning-sdk-squad/issues/2059