RANGER-5508: fix Runtime.exec parameters (#868)

Author: vyommani

ugsync/src/main/java/org/apache/ranger/unixusersync/process/UnixUserGroupBuilder.java

@@ -389,7 +389,7 @@ private void buildUnixUserList(String command) throws Throwable {
 
                 // "id" is same across Linux / BSD / MacOSX
                 // gids are used as id might return groups with spaces, ie "domain users"
-                Process process = Runtime.getRuntime().exec(new String[] {"bash", "-c", "id -G " + userName});
+                Process process = Runtime.getRuntime().exec(new String[] {"id", "-G", userName});
 
                 try {
                     reader = new BufferedReader(new InputStreamReader(process.getInputStream()));