RANGER-5643: fix Spotbugs and Checkstyle in InMemoryJAASConfiguration

Use entrySet iterators and StringBuilder for keyPrefix; remove blank line
after opening brace in test class.

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: ramk

agents-audit/core/src/main/java/org/apache/ranger/audit/utils/InMemoryJAASConfiguration.java

@@ -243,12 +243,15 @@ private void initialize(Properties properties) {
             }
         }
 
-        for (String jaasClient : jaasClients.keySet()) {
-            for (Integer index : jaasClients.get(jaasClient)) {
+        for (Map.Entry<String, SortedSet<Integer>> jaasClientEntry : jaasClients.entrySet()) {
+            String             jaasClient = jaasClientEntry.getKey();
+            SortedSet<Integer> indexList  = jaasClientEntry.getValue();
+
+            for (Integer index : indexList) {
                 String keyPrefix = JAAS_CONFIG_PREFIX_PARAM + jaasClient + ".";
 
                 if (index > -1) {
-                    keyPrefix = keyPrefix + index + ".";
+                    keyPrefix = new StringBuilder(keyPrefix).append(index).append('.').toString();
                 }
 
                 String keyParam        = keyPrefix + JAAS_CONFIG_LOGIN_MODULE_NAME_PARAM;
@@ -333,10 +336,9 @@ private void initialize(Properties properties) {
                     sb.append("\tloginModule: [").append(loginModuleName).append("]\n");
                     sb.append("\tcontrolFlag: [").append(loginControlFlag).append("]\n");
 
-                    for (String key : options.keySet()) {
-                        String val = options.get(key);
-
-                        sb.append("\tOptions:  [").append(key).append("] => [").append(val).append("]\n");
+                    for (Map.Entry<String, String> optionEntry : options.entrySet()) {
+                        sb.append("\tOptions:  [").append(optionEntry.getKey()).append("] => [")
+                                .append(optionEntry.getValue()).append("]\n");
                     }
 
                     LOG.debug(sb.toString());

agents-audit/core/src/test/java/org/apache/ranger/audit/utils/InMemoryJAASConfigurationTest.java

@@ -27,8 +27,7 @@
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 
-class InMemoryJAASConfigurationTest {
-
+public class InMemoryJAASConfigurationTest {
     @Test
     void resolveJaasPrincipalExpandsHostForServicePrincipal() throws Exception {
         String resolved = InMemoryJAASConfiguration.resolveJaasPrincipal(