Updates demo script to execute with bundled jdk (#3777)

Signed-off-by: Darshit Chanpura <dchanp@amazon.com>

build.gradle

@@ -256,6 +256,8 @@ test {
     jvmArgs += "-Xmx3072m"
     if (JavaVersion.current() > JavaVersion.VERSION_1_8) {
         jvmArgs += "--add-opens=java.base/java.io=ALL-UNNAMED"
+        // this is needed to reflect access system env map.
+        jvmArgs += "--add-opens=java.base/java.util=ALL-UNNAMED"
     }
     retry {
         failOnPassedAfterRetry = false
@@ -303,6 +305,8 @@ def setCommonTestConfig(Test task) {
     task.jvmArgs += "-Xmx3072m"
     if (JavaVersion.current() > JavaVersion.VERSION_1_8) {
         task.jvmArgs += "--add-opens=java.base/java.io=ALL-UNNAMED"
+        // this is needed to reflect access system env map.
+        task.jvmArgs += "--add-opens=java.base/java.util=ALL-UNNAMED"
     }
     task.retry {
         failOnPassedAfterRetry = false

src/main/java/org/opensearch/security/tools/democonfig/CertificateGenerator.java

@@ -19,14 +19,20 @@
 /**
  * This class creates demo certificate files
  */
-public class CertificateGenerator extends Installer {
+public class CertificateGenerator {
+
+    private final Installer installer;
+
+    public CertificateGenerator(Installer installer) {
+        this.installer = installer;
+    }
 
     /**
      * Creates demo super-admin, node and root certificates by iterating through Certificates enum
      */
     public void createDemoCertificates() {
         for (Certificates cert : Certificates.values()) {
-            String filePath = OPENSEARCH_CONF_DIR + File.separator + cert.getFileName();
+            String filePath = this.installer.OPENSEARCH_CONF_DIR + File.separator + cert.getFileName();
             writeCertificateToFile(filePath, cert.getContent());
         }
     }