Add dns to default list of disabled instrumentations (#33)

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*Description of changes:*


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aws-distro-opentelemetry-node-autoinstrumentation/src/register.ts

@@ -34,11 +34,11 @@ export function setAwsDefaultEnvironmentVariables(): void {
   if (!process.env.OTEL_PROPAGATORS) {
     process.env.OTEL_PROPAGATORS = 'xray,tracecontext,b3,b3multi';
   }
-  // Disable `@opentelemetry/instrumentation-fs` instrumentation by default
-  // This auto-instrumentation for the `fs` module would otherwise generate many low-value spans.
+  // Disable the following instrumentations by default
+  // This auto-instrumentation for the `fs` module generates many low-value spans. `dns` is similar.
   // https://github.com/open-telemetry/opentelemetry-js-contrib/issues/1344#issuecomment-1618993178
   if (!process.env.OTEL_NODE_DISABLED_INSTRUMENTATIONS) {
-    process.env.OTEL_NODE_DISABLED_INSTRUMENTATIONS = 'fs';
+    process.env.OTEL_NODE_DISABLED_INSTRUMENTATIONS = 'fs,dns';
   }
 }
 setAwsDefaultEnvironmentVariables();