message: set computeType, coreCount to object type to allow expressions
diff: "type": "object",
  "properties": {
  "computeType": {
  - "description": "Compute type of the cluster which will execute data flow job.",
  - "type": "string",
  - "enum": [
  - "General",
  - "MemoryOptimized",
  - "ComputeOptimized"
  - ],
  - "x-ms-enum": {
  - "name": "DataFlowComputeType",
  - "modelAsString": true
  - }
  + "description": "Compute type of the cluster which will execute data flow job. Possible values include: 'General', 'MemoryOptimized', 'ComputeOptimized'. Type: string (or Expression with resultType string)",
  + "type": "object"
  },
  "coreCount": {
  - "description": "Core count of the cluster which will execute data flow job. Supported values are: 8, 16, 32, 48, 80, 144 and 272.",
  - "type": "integer"
  + "description": "Core count of the cluster which will execute data flow job. Supported values are: 8, 16, 32, 48, 80, 144 and 272. Type: integer (or Expression with resultType integer)",
  + "type": "object"
  }
  }
  }
  