use opt-in flag for current semconv

Author: breedx-splk

instrumentation-api-incubator/src/main/java/io/opentelemetry/instrumentation/api/incubator/semconv/db/DbConnectionPoolMetrics.java

@@ -6,6 +6,7 @@
 package io.opentelemetry.instrumentation.api.incubator.semconv.db;
 
 import static io.opentelemetry.api.common.AttributeKey.stringKey;
+import static io.opentelemetry.instrumentation.api.internal.SemconvStability.emitStableDatabaseSemconv;
 
 import io.opentelemetry.api.OpenTelemetry;
 import io.opentelemetry.api.common.AttributeKey;
@@ -56,8 +57,10 @@ public static DbConnectionPoolMetrics create(
   }
 
   public ObservableLongMeasurement connections() {
+    String metricName =
+        emitStableDatabaseSemconv() ? "db.client.connection.count" : "db.client.connections.usage";
     return meter
-        .upDownCounterBuilder("db.client.connection.count")
+        .upDownCounterBuilder(metricName)
         .setUnit("{connections}")
         .setDescription(
             "The number of connections that are currently in state described by the state attribute.")