refactor(opentelemetry-sdk-node): use new get*FromEnv() function in NodeSDK's metrics setup (#5578)

Co-authored-by: Trent Mick <[email protected]>

Author: SBejga

experimental/packages/opentelemetry-sdk-node/src/sdk.ts

@@ -72,13 +72,12 @@ import { NodeSDKConfiguration } from './types';
 import {
   getBooleanFromEnv,
   getStringFromEnv,
-  diagLogLevelFromString,
   getStringListFromEnv,
+  diagLogLevelFromString,
 } from '@opentelemetry/core';
 import {
   getResourceDetectorsFromEnv,
   getSpanProcessorsFromEnv,
-  filterBlanksAndNulls,
   getPropagatorFromEnv,
 } from './utils';
 
@@ -115,11 +114,10 @@ function getValueInMillis(envName: string, defaultValue: number): number {
  */
 function configureMetricProviderFromEnv(): IMetricReader[] {
   const metricReaders: IMetricReader[] = [];
-  const metricsExporterList = process.env.OTEL_METRICS_EXPORTER?.trim();
-  if (!metricsExporterList) {
+  const enabledExporters = getStringListFromEnv('OTEL_METRICS_EXPORTER');
+  if (!enabledExporters) {
     return metricReaders;
   }
-  const enabledExporters = filterBlanksAndNulls(metricsExporterList.split(','));
 
   if (enabledExporters.length === 0) {
     diag.debug('OTEL_METRICS_EXPORTER is empty. Using default otlp exporter.');