[jmx-scraper] Create weaver model for jmx-scraper metrics open-telemetry#2072

 - fixed the updated desc in JvmIntegrationTest

Author: mcmho

jmx-scraper/src/integrationTest/java/io/opentelemetry/contrib/jmxscraper/target_systems/JvmIntegrationTest.java

@@ -90,23 +90,23 @@ protected MetricsVerifier createMetricsVerifier() {
             "jvm.memory.heap.committed",
             metric ->
                 metric
-                    .hasDescription("current heap usage")
+                    .hasDescription("current heap size")
                     .hasUnit("By")
                     .isGauge()
                     .hasDataPointsWithoutAttributes())
         .add(
             "jvm.memory.heap.init",
             metric ->
                 metric
-                    .hasDescription("current heap usage")
+                    .hasDescription("initial heap size")
                     .hasUnit("By")
                     .isGauge()
                     .hasDataPointsWithoutAttributes())
         .add(
             "jvm.memory.heap.max",
             metric ->
                 metric
-                    .hasDescription("current heap usage")
+                    .hasDescription("max heap size")
                     .hasUnit("By")
                     .isGauge()
                     .hasDataPointsWithoutAttributes())