Make `AutoConfiguredOpenTelemetrySdk`'s `resource` and `config` readable

Is your feature request related to a problem? Please describe.

Authors of OpenTelemetry integrations like the OpenTelemetry Maven Extension and the Jenkins OpenTelemetry Plugin are interested in read-only access to the config and resource loaded by the AutoConfiguredOpenTelemetrySdk during the build() creation method in order to ease troubleshooting and finding produced traces & metrics showing users the noteworthy

• Actual config like the exporters
• Actual resourcelike service.name and service.namespace

Describe the solution you'd like

Accessors to resource and config .

A solution to access the config is already available with i.o.s.autoconfigure.internal.AutoConfigureUtil#getConfig() | getStructuredConfig() .

I imagined:

• Either introduce AutoConfigureUtil#getResource()
• Or make #getResource(), getConfig(), and getStructuredConfig() public on AutoConfiguredOpenTelemetrySdk

This use cas is discussed with @SylvainJuge on

• https://github.com/open-telemetry/opentelemetry-java-contrib/pull/1434#pullrequestreview-2488186232

Describe alternatives you've considered

Today we rely on Java reflection in the Jenkisn OTel Plugin: https://github.com/open-telemetry/opentelemetry-java-contrib/pull/1434/files#diff-d2ce824d3b67fe3fe10a6aee588ea13e40a93d71743dc2982e2fc1d3ae797b0f

Additional context

Start by locating AutoConfiguredOpenTelemetrySdk and the internal AutoConfigureUtil methods getResource(), getConfig(), and getStructuredConfig(). Review the linked integration use cases and pull-request discussion, then verify that read-only access exposes the loaded resource and configuration without reflection.