[Rule-based Auto-tagging] Bug fix on Update Rule API (opensearch-project#19497)

Signed-off-by: Ruirui Zhang <mariazrr@amazon.com>

Author: ruai0511

CHANGELOG.md

@@ -14,6 +14,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Add a toBuilder method in EngineConfig to support easy modification of configs([#19054](https://github.com/opensearch-project/OpenSearch/pull/19054))
 - Add StoreFactory plugin interface for custom Store implementations([#19091](https://github.com/opensearch-project/OpenSearch/pull/19091))
 - Use S3CrtClient for higher throughput while uploading files to S3 ([#18800](https://github.com/opensearch-project/OpenSearch/pull/18800))
+- [Rule-based Auto-tagging] bug fix on Update Rule API with multiple attributes ([#19497](https://github.com/opensearch-project/OpenSearch/pull/19497))
 - Add a dynamic setting to change skip_cache_factor and min_frequency for querycache ([#18351](https://github.com/opensearch-project/OpenSearch/issues/18351))
 - Add overload constructor for Translog to accept Channel Factory as a parameter ([#18918](https://github.com/opensearch-project/OpenSearch/pull/18918))
 - Add subdirectory-aware store module with recovery support ([#19132](https://github.com/opensearch-project/OpenSearch/pull/19132))

modules/autotagging-commons/common/src/main/java/org/opensearch/rule/RuleUtils.java

@@ -105,12 +105,16 @@ public static Optional<String> getDuplicateRuleId(Rule rule, List<Rule> ruleList
      */
     public static Rule composeUpdatedRule(Rule originalRule, UpdateRuleRequest request, FeatureType featureType) {
         String requestDescription = request.getDescription();
-        Map<Attribute, Set<String>> requestMap = request.getAttributeMap();
         String requestLabel = request.getFeatureValue();
+        Map<Attribute, Set<String>> requestMap = request.getAttributeMap();
+        Map<Attribute, Set<String>> updatedAttributeMap = new HashMap<>(originalRule.getAttributeMap());
+        if (requestMap != null && !requestMap.isEmpty()) {
+            updatedAttributeMap.putAll(requestMap);
+        }
         return new Rule(
             originalRule.getId(),
             requestDescription == null ? originalRule.getDescription() : requestDescription,
-            requestMap == null || requestMap.isEmpty() ? originalRule.getAttributeMap() : requestMap,
+            updatedAttributeMap,
             featureType,
             requestLabel == null ? originalRule.getFeatureValue() : requestLabel,
             Instant.now().toString()