Enhance resource change event on SimpleInstanceEnabler.

Author: sbernard31

leshan-client-core/src/main/java/org/eclipse/leshan/client/resource/SimpleInstanceEnabler.java

@@ -132,6 +132,11 @@ public WriteResponse write(LwM2mServer server, boolean replace, int resourceid,
                 }
             });
 
+            // also add resource path as we can consider that modifying child is a modification.
+            if (!changedResources.isEmpty()) {
+                changedResources.add(getResourcePath(resourceid));
+            }
+
         } else {
             if (!newValue.equals(previousValue)) {
                 changedResources.add(getResourcePath(resourceid));