align gc label name with opentelemetry spec

Signed-off-by: gniadeck <77535280+gniadeck@users.noreply.github.com>

Author: gniadeck

prometheus-metrics-instrumentation-jvm/src/main/java/io/prometheus/metrics/instrumentation/jvm/JvmGarbageCollectorMetrics.java

@@ -84,7 +84,7 @@ private void registerGCDurationHistogram(PrometheusRegistry registry) {
             .name(JVM_GC_DURATION_SECONDS)
             .help("JVM GC pause duration histogram.")
             .unit(Unit.SECONDS)
-            .labelNames("gc", "action", "cause")
+            .labelNames("name", "action", "cause")
             .classicUpperBounds(buckets)
             .register(registry);