message: Update trace telemetry to include properties in part b'
diff: @@ -17,4 +17,9 @@ export interface ITraceTelemetry {
  * @memberof ITraceTelemetry
  */
  severityLevel?: SeverityLevel;
  +
  + /**
  + * property bag to contain an extension to domain properties - extension to Part B
  + */
  + properties?: { [key: string]: string };
  }
  