[Test] Fix - mutateInstance in BulkUpdateApiKeyRequestSerializationTests not unique (elastic#103917)

Leftover `+ 1` from previous testing strategy that should have been
removed. 

Relates: elastic#103913

Author: jfreden

x-pack/plugin/core/src/test/java/org/elasticsearch/xpack/core/security/action/apikey/BulkUpdateApiKeyRequestSerializationTests.java

@@ -7,7 +7,6 @@
 
 package org.elasticsearch.xpack.core.security.action.apikey;
 
-import org.apache.lucene.tests.util.LuceneTestCase;
 import org.elasticsearch.TransportVersions;
 import org.elasticsearch.common.io.stream.Writeable;
 import org.elasticsearch.core.TimeValue;
@@ -21,7 +20,6 @@
 
 import static org.hamcrest.Matchers.nullValue;
 
-@LuceneTestCase.AwaitsFix(bugUrl = "https://github.com/elastic/elasticsearch/issues/103913")
 public class BulkUpdateApiKeyRequestSerializationTests extends AbstractWireSerializingTestCase<BulkUpdateApiKeyRequest> {
     public void testSerializationBackwardsCompatibility() throws IOException {
         BulkUpdateApiKeyRequest testInstance = createTestInstance();
@@ -67,7 +65,7 @@ protected BulkUpdateApiKeyRequest mutateInstance(BulkUpdateApiKeyRequest instanc
             instance.getIds(),
             instance.getRoleDescriptors(),
             metadata,
-            TimeValue.parseTimeValue((days + 1) + "d", null, "expiration")
+            TimeValue.parseTimeValue(days + "d", null, "expiration")
         );
     }
 }