Fix language server telemetry event name choice (microsoft#3032)

microsoft#3003 cherry picked a change to forward language server telemetry, but it accessed the wrong member of the event, causing the default to always be used.

Author: jakebailey

src/client/activation/languageServer/languageServer.ts

@@ -166,7 +166,7 @@ export class LanguageServerExtensionActivator implements IExtensionActivator {
  try {
  await this.startLanguageClient();
  this.languageClient.onTelemetry(telemetryEvent => {
- const eventName = telemetryEvent.Name ? telemetryEvent.Name : PYTHON_LANGUAGE_SERVER_TELEMETRY;
+ const eventName = telemetryEvent.EventName ? telemetryEvent.EventName : PYTHON_LANGUAGE_SERVER_TELEMETRY;
  sendTelemetryEvent(eventName, telemetryEvent.Measurements, telemetryEvent.Properties);
  });
  return true;