Do not use system properties when building the HttpAsyncClient (#27829)

This commit removes the usage of system properties for the HttpAsyncClient as this overrides some
defaults that we intentionally change. In order to set the default SSLContext to the system context
we set the SSLContext on the builder explicitly.

Closes #27827

Author: jaymode

client/rest/src/main/java/org/elasticsearch/client/RestClientBuilder.java

@@ -28,7 +28,9 @@
 import org.apache.http.impl.nio.client.HttpAsyncClientBuilder;
 import org.apache.http.nio.conn.SchemeIOSessionStrategy;
 
+import javax.net.ssl.SSLContext;
 import java.security.AccessController;
+import java.security.NoSuchAlgorithmException;
 import java.security.PrivilegedAction;
 import java.util.Objects;
 
@@ -200,20 +202,25 @@ private CloseableHttpAsyncClient createHttpClient() {
             requestConfigBuilder = requestConfigCallback.customizeRequestConfig(requestConfigBuilder);
         }
 
-        HttpAsyncClientBuilder httpClientBuilder = HttpAsyncClientBuilder.create().setDefaultRequestConfig(requestConfigBuilder.build())
+        try {
+            HttpAsyncClientBuilder httpClientBuilder = HttpAsyncClientBuilder.create().setDefaultRequestConfig(requestConfigBuilder.build())
                 //default settings for connection pooling may be too constraining
-                .setMaxConnPerRoute(DEFAULT_MAX_CONN_PER_ROUTE).setMaxConnTotal(DEFAULT_MAX_CONN_TOTAL).useSystemProperties();
-        if (httpClientConfigCallback != null) {
-            httpClientBuilder = httpClientConfigCallback.customizeHttpClient(httpClientBuilder);
-        }
-
-        final HttpAsyncClientBuilder finalBuilder = httpClientBuilder;
-        return AccessController.doPrivileged(new PrivilegedAction<CloseableHttpAsyncClient>() {
-            @Override
-            public CloseableHttpAsyncClient run() {
-                return finalBuilder.build();
+                .setMaxConnPerRoute(DEFAULT_MAX_CONN_PER_ROUTE).setMaxConnTotal(DEFAULT_MAX_CONN_TOTAL)
+                .setSSLContext(SSLContext.getDefault());
+            if (httpClientConfigCallback != null) {
+                httpClientBuilder = httpClientConfigCallback.customizeHttpClient(httpClientBuilder);
             }
-        });
+
+            final HttpAsyncClientBuilder finalBuilder = httpClientBuilder;
+            return AccessController.doPrivileged(new PrivilegedAction<CloseableHttpAsyncClient>() {
+                @Override
+                public CloseableHttpAsyncClient run() {
+                    return finalBuilder.build();
+                }
+            });
+        } catch (NoSuchAlgorithmException e) {
+            throw new IllegalStateException("could not create the default ssl context", e);
+        }
     }
 
     /**