use index for slow log test that works

Author: markjhoy

x-pack/plugin/security/qa/security-basic/src/javaRestTest/java/org/elasticsearch/xpack/security/SecuritySlowLogIT.java

@@ -311,7 +311,7 @@ private static List<TestIndexData> randomTestIndexData() throws IOException {
         List<TestIndexData> testData = new ArrayList<>();
         for (int i = 0; i < randomIntBetween(1, 10); i++) {
             TestIndexData randomTestData = new TestIndexData(
-                "search-" + randomAlphaOfLengthBetween(5, 10).toLowerCase() + "-" + i,
+                "agentless-" + randomAlphaOfLengthBetween(5, 10).toLowerCase() + "-" + i,
                 randomBoolean(),
                 randomBoolean(),
                 randomBoolean(),