Fix mock object creation in DelegatePki HLRC test (#84468)

This test would create objects with an authentication_type of "API_KEY",
but with a real authentication realm (rather than the API key synthetic
realm).

It is not possible to create an object like that on the server, so the
test was asserting behaviour that cannot exist, and should not be
subject to test constraints.

This commit fixes the mock object creation to always create more
realistic objects.

Relates: #84396 Resolves: #84433

client/rest-high-level/src/test/java/org/elasticsearch/client/security/DelegatePkiAuthenticationResponseTests.java

@@ -10,6 +10,7 @@
 
 import org.elasticsearch.Version;
 import org.elasticsearch.client.AbstractResponseTestCase;
+import org.elasticsearch.common.Strings;
 import org.elasticsearch.core.TimeValue;
 import org.elasticsearch.xcontent.XContentParser;
 import org.elasticsearch.xcontent.XContentType;
@@ -26,7 +27,6 @@
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.is;
 
-@AbstractResponseTestCase.AwaitsFix(bugUrl = "https://github.com/elastic/elasticsearch/issues/84433")
 public class DelegatePkiAuthenticationResponseTests extends AbstractResponseTestCase<
     org.elasticsearch.xpack.core.security.action.DelegatePkiAuthenticationResponse,
     DelegatePkiAuthenticationResponse> {
@@ -56,8 +56,15 @@ protected void assertInstances(
         assertThat(serverTestInstance.getExpiresIn(), is(clientInstance.getExpiresIn()));
         assertThat(clientInstance.getType(), is("Bearer"));
         AuthenticateResponse serverAuthenticationResponse = createServerAuthenticationResponse(serverTestInstance.getAuthentication());
-        User user = serverTestInstance.getAuthentication().getUser();
-        assertThat(serverAuthenticationResponse, equalTo(clientInstance.getAuthentication()));
+        assertThat(
+            "Expected responses to be equal: server=["
+                + Strings.toString(serverAuthenticationResponse)
+                + "], client=["
+                + Strings.toString(clientInstance.getAuthentication())
+                + "]",
+            serverAuthenticationResponse,
+            equalTo(clientInstance.getAuthentication())
+        );
     }
 
     protected Authentication createAuthentication() {
@@ -77,21 +84,36 @@ protected Authentication createAuthentication() {
         }
         final String fullName = randomFrom(random(), null, randomAlphaOfLengthBetween(0, 4));
         final String email = randomFrom(random(), null, randomAlphaOfLengthBetween(0, 4));
-        final boolean enabled = randomBoolean();
-        final String authenticationRealmName = randomAlphaOfLength(5);
-        final String authenticationRealmType = randomFrom("file", "native", "ldap", "active_directory", "saml", "kerberos");
-        final String lookupRealmName = randomAlphaOfLength(5);
-        final String lookupRealmType = randomFrom("file", "native", "ldap", "active_directory", "saml", "kerberos");
+
         final String nodeName = randomAlphaOfLengthBetween(1, 10);
+        final Authentication.RealmRef authenticationRealm;
+        final Authentication.RealmRef lookupRealm;
         final Authentication.AuthenticationType authenticationType = randomFrom(Authentication.AuthenticationType.values());
         if (Authentication.AuthenticationType.API_KEY.equals(authenticationType)) {
+            authenticationRealm = new Authentication.RealmRef(
+                AuthenticationField.API_KEY_REALM_NAME,
+                AuthenticationField.API_KEY_REALM_TYPE,
+                nodeName
+            );
+            lookupRealm = null;
             metadata.put(AuthenticationField.API_KEY_ID_KEY, randomAlphaOfLengthBetween(1, 10));
             metadata.put(AuthenticationField.API_KEY_NAME_KEY, randomBoolean() ? null : randomAlphaOfLengthBetween(1, 10));
+        } else {
+            authenticationRealm = new Authentication.RealmRef(
+                randomAlphaOfLength(5),
+                randomFrom("file", "native", "ldap", "active_directory", "saml", "kerberos"),
+                nodeName
+            );
+            lookupRealm = new Authentication.RealmRef(
+                randomAlphaOfLength(5),
+                randomFrom("file", "native", "ldap", "active_directory", "saml", "kerberos"),
+                nodeName
+            );
         }
         return new Authentication(
             new User(username, roles, fullName, email, metadata, true),
-            new Authentication.RealmRef(authenticationRealmName, authenticationRealmType, nodeName),
-            new Authentication.RealmRef(lookupRealmName, lookupRealmType, nodeName),
+            authenticationRealm,
+            lookupRealm,
             Version.CURRENT,
             authenticationType,
             metadata