[challenge 4] - data export from Iot Central

[lenisha]

current instructions ask to use Iot Central Data Export (Legacy), we have tested it with newer version of Data Export and it worked with following changes:

• setup Data Export Add destinattion pointing to IotConnector EventHubs Connection String and export Telemetry:

• update device template in Iot Connector as per https://github.com/microsoft/iomt-fhir/blob/master/docs/Configuration.md#iotcentraljsonpathcontenttemplate

  {
  "templateType": "CollectionContent",
  "template": [
      {
          "templateType": "IotCentralJsonPathContent",
          "template": {
              "typeName": "heartrate",
              "typeMatchExpression": "$..[?(@telemetry.HeartRate)]",
              "values": [
                  {
                      "required": "true",
                      "valueExpression": "$.telemetry.HeartRate",
                      "valueName": "hr"
                  }
              ]
          }
      }
  ]
  }