[exporter/datadog] Change noAPMStatsFeatureGate log from warn to info

[liustanley]

Description:

Changes log introduced in #31981 from a warn log to an info log, since info is more appropriate for this message.

❯ ./bin/otelcontribcol_darwin_arm64
2024-04-03T11:04:48.974-0400    info    service@v0.97.1-0.20240327181407-1038b67c85a0/telemetry.go:55   Setting up own telemetry...
2024-04-03T11:04:48.974-0400    info    service@v0.97.1-0.20240327181407-1038b67c85a0/telemetry.go:97   Serving metrics {"address": ":8888", "level": "Basic"}
2024-04-03T11:04:48.975-0400    debug   exporter@v0.97.1-0.20240327181407-1038b67c85a0/exporter.go:273  Beta component. May change in the future.       {"kind": "exporter", "data_type": "traces", "name": "datadog/api"}
2024-04-03T11:04:48.975-0400    info    datadogexporter@v0.97.0/factory.go:386  Trace metrics are now disabled in the Datadog Exporter by default. To continue receiving Trace Metrics, configure the Datadog Connector or disable the feature gate.    {"kind": "exporter", "data_type": "traces", "name": "datadog/api", "documentation": "https://docs.datadoghq.com/opentelemetry/guide/migration/", "feature gate ID": "exporter.datadogexporter.DisableAPMStats"}

Link to tracking Issue:

Testing:

Documentation: