Fix ReloadDetailsTests compilation

Author: Christoph Büscher

x-pack/plugin/core/src/test/java/org/elasticsearch/xpack/core/action/ReloadDetailsTests.java

@@ -11,15 +11,17 @@
 import org.elasticsearch.xpack.core.action.ReloadAnalyzersResponse.ReloadDetails;
 
 import java.io.IOException;
+import java.util.Arrays;
 import java.util.HashSet;
 import java.util.Set;
 
 public class ReloadDetailsTests extends AbstractWireSerializingTestCase<ReloadDetails> {
 
     @Override
     protected ReloadDetails createTestInstance() {
-        return new ReloadDetails(randomAlphaOfLengthBetween(5, 10), Set.of(generateRandomStringArray(5, 5, false)),
-                Set.of(generateRandomStringArray(5, 5, false)));
+        return new ReloadDetails(randomAlphaOfLengthBetween(5, 10), 
+                new HashSet<>(Arrays.asList(generateRandomStringArray(5, 5, false))),
+                new HashSet<>(Arrays.asList(generateRandomStringArray(5, 5, false))));
     }
 
     @Override