Add system properties to metadata yaml (#1829)

Author: laurit

.github/workflows/pr.yaml

@@ -217,3 +217,9 @@ jobs:
       # verify that metadata generation succeeds
       - name: Generate metadata
         run: ./gradlew :metadata-generator:generateMetadata --no-daemon
+
+      - name: Upload metadata yaml
+        uses: actions/[email protected]
+        with:
+          name: splunk-otel-java-metadata.yaml
+          path: metadata-generator/build/splunk-otel-java-metadata.yaml