**Build scan:**
https://gradle-enterprise.elastic.co/s/piyf2ga5fnjjg/tests/:modules:repository-gcs:test/org.elasticsearch.repositories.gcs.GoogleCloudStorageClientSettingsTests/testLoadsProxySettings

**Reproduction line:**
```
./gradlew ':modules:repository-gcs:test' --tests "org.elasticsearch.repositories.gcs.GoogleCloudStorageClientSettingsTests.testLoadsProxySettings" -Dtests.seed=147C59CC808694D0 -Dtests.locale=mk -Dtests.timezone=America/Cordoba -Druntime.java=17
```

**Applicable branches:**
main

**Reproduces locally?:**
Yes

**Failure history:**
https://gradle-enterprise.elastic.co/scans/tests?tests.container=org.elasticsearch.repositories.gcs.GoogleCloudStorageClientSettingsTests&tests.test=testLoadsProxySettings

**Failure excerpt:**
```
java.lang.IllegalArgumentException: port out of range:65536

  at __randomizedtesting.SeedInfo.seed([147C59CC808694D0:D0F78F252FEAAD7A]:0)
  at java.net.InetSocketAddress.checkPort(InetSocketAddress.java:152)
  at java.net.InetSocketAddress.<init>(InetSocketAddress.java:197)
  at org.elasticsearch.repositories.gcs.GoogleCloudStorageClientSettingsTests.testLoadsProxySettings(GoogleCloudStorageClientSettingsTests.java:135)
  at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(NativeMethodAccessorImpl.java:-2)
  at jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
  at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
  at java.lang.reflect.Method.invoke(Method.java:568)
  at com.carrotsearch.randomizedtesting.RandomizedRunner.invoke(RandomizedRunner.java:1758)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$8.evaluate(RandomizedRunner.java:946)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$9.evaluate(RandomizedRunner.java:982)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$10.evaluate(RandomizedRunner.java:996)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at org.apache.lucene.tests.util.TestRuleSetupTeardownChained$1.evaluate(TestRuleSetupTeardownChained.java:48)
  at org.apache.lucene.tests.util.AbstractBeforeAfterRule$1.evaluate(AbstractBeforeAfterRule.java:43)
  at org.apache.lucene.tests.util.TestRuleThreadAndTestName$1.evaluate(TestRuleThreadAndTestName.java:45)
  at org.apache.lucene.tests.util.TestRuleIgnoreAfterMaxFailures$1.evaluate(TestRuleIgnoreAfterMaxFailures.java:60)
  at org.apache.lucene.tests.util.TestRuleMarkFailure$1.evaluate(TestRuleMarkFailure.java:44)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at com.carrotsearch.randomizedtesting.ThreadLeakControl$StatementRunner.run(ThreadLeakControl.java:390)
  at com.carrotsearch.randomizedtesting.ThreadLeakControl.forkTimeoutingTask(ThreadLeakControl.java:843)
  at com.carrotsearch.randomizedtesting.ThreadLeakControl$3.evaluate(ThreadLeakControl.java:490)
  at com.carrotsearch.randomizedtesting.RandomizedRunner.runSingleTest(RandomizedRunner.java:955)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$5.evaluate(RandomizedRunner.java:840)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$6.evaluate(RandomizedRunner.java:891)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$7.evaluate(RandomizedRunner.java:902)
  at org.apache.lucene.tests.util.AbstractBeforeAfterRule$1.evaluate(AbstractBeforeAfterRule.java:43)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at org.apache.lucene.tests.util.TestRuleStoreClassName$1.evaluate(TestRuleStoreClassName.java:38)
  at com.carrotsearch.randomizedtesting.rules.NoShadowingOrOverridesOnMethodsRule$1.evaluate(NoShadowingOrOverridesOnMethodsRule.java:40)
  at com.carrotsearch.randomizedtesting.rules.NoShadowingOrOverridesOnMethodsRule$1.evaluate(NoShadowingOrOverridesOnMethodsRule.java:40)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at org.apache.lucene.tests.util.TestRuleAssertionsRequired$1.evaluate(TestRuleAssertionsRequired.java:53)
  at org.apache.lucene.tests.util.AbstractBeforeAfterRule$1.evaluate(AbstractBeforeAfterRule.java:43)
  at org.apache.lucene.tests.util.TestRuleMarkFailure$1.evaluate(TestRuleMarkFailure.java:44)
  at org.apache.lucene.tests.util.TestRuleIgnoreAfterMaxFailures$1.evaluate(TestRuleIgnoreAfterMaxFailures.java:60)
  at org.apache.lucene.tests.util.TestRuleIgnoreTestSuites$1.evaluate(TestRuleIgnoreTestSuites.java:47)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at com.carrotsearch.randomizedtesting.ThreadLeakControl$StatementRunner.run(ThreadLeakControl.java:390)
  at com.carrotsearch.randomizedtesting.ThreadLeakControl.lambda$forkTimeoutingTask$0(ThreadLeakControl.java:850)
  at java.lang.Thread.run(Thread.java:833)

```
modules/repository-gcs/src/test/java/org/elasticsearch/repositories/gcs/GoogleCloudStorageClientSettingsTests.java
var proxyServer = new MockHttpProxyServer() {
            @Override
            public void handle(HttpRequest request, HttpResponse response, HttpContext context) {
                assertEquals("POST http://oauth2.googleapis.com/oauth2/token HTTP/1.1", request.getRequestLine().toString());
                String body = """
                    {
                        "access_token": "proxy_access_token",
                        "token_type": "bearer",
                        "expires_in": 3600
                    }
                    """;
                response.setEntity(new StringEntity(body, ContentType.TEXT_PLAIN));
            }
        };
        try (proxyServer) {
            var proxy = new Proxy(Proxy.Type.HTTP, new InetSocketAddress(InetAddress.getLoopbackAddress(), proxyServer.getPort()));
            ServiceAccountCredentials credentials = loadCredential(settings, clientName, proxy);
            assertNotNull(credentials);
            assertEquals("proxy_access_token", SocketAccess.doPrivilegedIOException(credentials::refreshAccessToken).getTokenValue());
        }
    }
    
    private Tuple<Map<String, GoogleCloudStorageClientSettings>, Settings> randomClients(
        final int nbClients,
        final List<Setting<?>> deprecationWarnings
    ) throws Exception {
        final Map<String, GoogleCloudStorageClientSettings> expectedClients = new HashMap<>();
        final Settings.Builder settings = Settings.builder();
        final MockSecureSettings secureSettings = new MockSecureSettings();
        for (int i = 0; i < nbClients; i++) {