adding telemtetry to detect machine id guids (#67955)

* adding telemtetry to detect machine id guids

* better condition

* stricter

* fix for regex

src/vs/platform/telemetry/common/telemetryService.ts

@@ -61,6 +61,17 @@ export class TelemetryService implements ITelemetryService {
 			*/
 			this.publicLog('optInStatus', { optIn: this._userOptIn });
 		}
+
+		this._commonProperties.then(values => {
+			const isHashedId = /^[a-f0-9]+$/i.test(values['common.machineId']);
+
+			/* __GDPR__
+				"machineIdFallback" : {
+					"usingFallbackGuid" : { "classification": "SystemMetaData", "purpose": "BusinessInsight", "isMeasurement": true }
+				}
+			*/
+			this.publicLog('machineIdFallback', { usingFallbackGuid: !isHashedId });
+		});
 	}
 
 	private _updateUserOptIn(): void {