add label to STT/TTS alerts (#1468)

* add label to STT/TTS alerts

* update time-series

lib/tasks/tts-task.js

@@ -274,6 +274,7 @@ class TtsTask extends Task {
           account_sid,
           alert_type: AlertType.TTS_NOT_PROVISIONED,
           vendor,
+          label,
           target_sid: cs.callSid
         }).catch((err) => this.logger.info({err}, 'Error generating alert for no tts'));
         throw new SpeechCredentialError('no provisioned speech credentials for TTS');
@@ -360,6 +361,7 @@ class TtsTask extends Task {
             account_sid: cs.accountSid,
             alert_type: AlertType.TTS_FAILURE,
             vendor,
+            label,
             detail: err.message,
             target_sid: cs.callSid
           }).catch((err) => this.logger.info({err}, 'Error generating alert for tts failure'));