NIFI-8709 - added XSAnyImpl in attribute check for group

Signed-off-by: Pierre Villard <pierre.villard.fr@gmail.com>

This closes #5164.
diff --git a/nifi-nar-bundles/nifi-framework-bundle/nifi-framework/nifi-web/nifi-web-security/src/main/java/org/apache/nifi/web/security/saml/impl/StandardSAMLService.java b/nifi-nar-bundles/nifi-framework-bundle/nifi-framework/nifi-web/nifi-web-security/src/main/java/org/apache/nifi/web/security/saml/impl/StandardSAMLService.java
index d1a1e97..bbcff0c 100644
--- a/nifi-nar-bundles/nifi-framework-bundle/nifi-framework/nifi-web/nifi-web-security/src/main/java/org/apache/nifi/web/security/saml/impl/StandardSAMLService.java
+++ b/nifi-nar-bundles/nifi-framework-bundle/nifi-framework/nifi-web/nifi-web-security/src/main/java/org/apache/nifi/web/security/saml/impl/StandardSAMLService.java
@@ -36,6 +36,7 @@
 import org.opensaml.xml.XMLObject;
 import org.opensaml.xml.encryption.DecryptionException;
 import org.opensaml.xml.schema.XSString;
+import org.opensaml.xml.schema.impl.XSAnyImpl;
 import org.opensaml.xml.validation.ValidationException;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -375,8 +376,13 @@
                         final String groupName = valueXSString.getValue();
                         LOGGER.debug("Found group {} for {}", groupName, userIdentity);
                         groups.add(groupName);
+                    } else if (value instanceof XSAnyImpl) {
+                        final XSAnyImpl valueXSAnyImpl = (XSAnyImpl) value;
+                        final String groupName = valueXSAnyImpl.getTextContent();
+                        LOGGER.debug("Found group {} for {}", groupName, userIdentity);
+                        groups.add(groupName);
                     } else {
-                        LOGGER.debug("Value was not XSString, but was " + value.getClass().getCanonicalName());
+                        LOGGER.debug("Value was not XSString and XSAnyImpl, but was " + value.getClass().getCanonicalName());
                     }
                 }
             }