[ALS-5514] Evaluate user metadata with isNotBlank to handle the null …

…case.

This was to fix getGeneralMetadata throwing NPE on isEmpty() if its null.

pic-sure-auth-services/src/main/java/edu/harvard/hms/dbmi/avillach/auth/service/auth/OktaOAuthAuthenticationService.java

@@ -130,7 +130,7 @@ private User loadUser(JsonNode introspectResponse) {
             }
 
             // Add metadata to the user upon logging in if it doesn't exist
-            if (user.getGeneralMetadata().isEmpty()) {
+            if (StringUtils.isBlank(user.getGeneralMetadata())) {
                 logger.info("Adding metadata to user: " + user.getUuid());
                 // JsonNode is immutable, so we need to convert it to a ObjectNode
                 ObjectNode objectNode = JAXRSConfiguration.objectMapper.createObjectNode();