The plugin now outputs to "generated/sources". The IDE configuration
explicitly adding the folders to the source sets hasn't been needed for
some years.
The GSON upgrade slightly changed an error string, so the test was
updated to be less of a change detector.
Some OpenTelemetry dependencies are alpha versions, so needed an
adjustment in build.gradle to accept the versions. Similarly, Undertow
includes Final in its version numbers which needs to be accepted.
Add gRPC OpenTelemetry example. The example uses Prometheus exporter to export metrics and can be verified locally.
It also provides an example using LoggingMetricExporter to export and log the metrics using java.util.logging.