REST API should return 400 instead of 500

Keycloak/RH-SSO does not handle empty POST data in proper way when using /users and /groups admin REST interface of RH-SSO.

When making POST requests to /users and /groups REST interfaces with empty data RH-SSO returns HTTP/1.1 500 Internal server error

Eg.

curl -fsSL \
-H "Authorization: bearer $TOKEN" \
-H "Content-Type: application/json" \
"https://${RH-SSO-ENDPOINT}/admin/realms/${REALM}/users" \
-X POST
-d '{}' or if -d is not provided

HTTP/1.1 500 Internal server error

This results in null pointer exception in RH-SSO server.log as no data is provide which seems to be expected behavior.
Keycloak/RH-SSO should rather say 400 bad request instead of 500 Internal server error as this creates wrong impression also NPE exception not handled correctly.