Add protocol and version to observation attributes

Author: acogoluegnes

src/main/java/com/rabbitmq/client/observation/micrometer/DefaultPublishObservationConvention.java

@@ -56,7 +56,9 @@ private String exchange(String destination) {
   public KeyValues getLowCardinalityKeyValues(PublishContext context) {
     return KeyValues.of(
         LowCardinalityTags.MESSAGING_OPERATION.withValue("publish"),
-        LowCardinalityTags.MESSAGING_SYSTEM.withValue("rabbitmq"));
+        LowCardinalityTags.MESSAGING_SYSTEM.withValue("rabbitmq"),
+        LowCardinalityTags.NET_PROTOCOL_NAME.withValue("amqp"),
+        LowCardinalityTags.NET_PROTOCOL_VERSION.withValue("0.9.1"));
   }
 
   @Override

src/main/java/com/rabbitmq/client/observation/micrometer/RabbitMqObservationDocumentation.java

@@ -107,7 +107,23 @@ public String asString() {
       public String asString() {
         return "messaging.operation";
       }
-    }
+    },
+
+    NET_PROTOCOL_NAME {
+
+      @Override
+      public String asString() {
+        return "net.protocol.name";
+      }
+    },
+
+    NET_PROTOCOL_VERSION {
+
+      @Override
+      public String asString() {
+        return "net.protocol.version";
+      }
+    },
   }
 
   /** High cardinality tags. */