Improve performance for resolving derived fields (#16564) (#16566)

Doing the type check before the string comparison makes it much faster to resolve derived fields.


(cherry picked from commit e07499a)

Signed-off-by: Robson Araujo <robson.araujo@glean.com>
Signed-off-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

server/src/main/java/org/opensearch/index/mapper/DefaultDerivedFieldResolver.java

@@ -72,7 +72,7 @@ public Set<String> resolvePattern(String pattern) {
         Set<String> derivedFields = new HashSet<>();
         if (queryShardContext != null && queryShardContext.getMapperService() != null) {
             for (MappedFieldType fieldType : queryShardContext.getMapperService().fieldTypes()) {
-                if (Regex.simpleMatch(pattern, fieldType.name()) && fieldType instanceof DerivedFieldType) {
+                if (fieldType instanceof DerivedFieldType && Regex.simpleMatch(pattern, fieldType.name())) {
                     derivedFields.add(fieldType.name());
                 }
             }