message: Change type of Ssis actitvity's packagePath, runtime, loggingLevel and
  environmentPath from string to object, so that we can use expression for
  these properties
diff: "$ref": "#/definitions/SSISPackageLocation"
  },
  "runtime": {
  - "description": "Specifies the runtime to execute SSIS package.",
  - "type": "string",
  - "enum": [
  - "x64",
  - "x86"
  - ],
  - "x-ms-enum": {
  - "name": "SSISExecutionRuntime",
  - "modelAsString": true
  - }
  + "description": "Specifies the runtime to execute SSIS package. The value should be \"x86\" or \"x64\". Type: string (or Expression with resultType string).",
  + "type": "object"
  },
  "loggingLevel": {
  - "description": "The logging level of SSIS package execution.",
  - "type": "string"
  + "description": "The logging level of SSIS package execution. Type: string (or Expression with resultType string).",
  + "type": "object"
  },
  "environmentPath": {
  - "description": "The environment path to execute the SSIS package.",
  - "type": "string"
  + "description": "The environment path to execute the SSIS package. Type: string (or Expression with resultType string).",
  + "type": "object"
  },
  "connectVia": {
  "description": "The integration runtime reference.",
  "type" : "object",
  "properties": {
  "packagePath": {
  - "description": "The SSIS package path.",
  - "type": "string"
  + "description": "The SSIS package path. Type: string (or Expression with resultType string).",
  + "type": "object"
  }
  },
  "required": [
  