[exporter/datadogexporter] update ConfigMap verbiage in system metrics for clarity (#31990)

**Description:** 
Changing "Comment out..." to "Uncomment" as "comment out" usually means
to remove parsable code by adding comment notation, not removing
comments to make the code parsable. This could cause some confusion.

Author: ElRojo

exporter/datadogexporter/examples/k8s-chart/configmap.yaml

@@ -40,7 +40,7 @@ data:
         include:
           # This will ensure that logs from the following path are collected.
           - /var/log/**/*otel-collector*/*.log
-      # # Comment out this block below to get access to system metrics regarding
+      # # Uncomment this block below to get access to system metrics regarding
       # # the OpenTelemetry Collector and its environment, such as spans or metrics
       # # processed, running and sent, queue sizes, uptime, k8s information
       # # and much more.