fix(observation): create a generic log event

Instead of a log event for each different log message.

Closes CAMEL-21854

Author: squakez

components/camel-observation/src/main/java/org/apache/camel/observation/MicrometerObservationSpanAdapter.java

@@ -108,13 +108,9 @@ public void setLowCardinalityTag(String key, Boolean value) {
     public void log(Map<String, String> fields) {
         String event = fields.get("event");
         if ("error".equalsIgnoreCase(event)) {
-            if (fields.containsKey("message")) {
-                observation.error(new RuntimeException(fields.get("message")));
-            } else {
-                setError(true);
-            }
+            setError(true);
         } else {
-            observation.event(() -> getMessageNameFromFields(fields));
+            observation.event(() -> DEFAULT_EVENT_NAME);
         }
     }
 
@@ -139,14 +135,6 @@ public AutoCloseable makeCurrent() {
         return observation.openScope();
     }
 
-    String getMessageNameFromFields(Map<String, ?> fields) {
-        Object eventValue = fields == null ? null : fields.get("message");
-        if (eventValue != null) {
-            return eventValue.toString();
-        }
-        return DEFAULT_EVENT_NAME;
-    }
-
     public void setCorrelationContextItem(String key, String value) {
         Baggage baggage = tracer.createBaggage(key);
         Span span = getTracingContext().getSpan();