Follow the instructions in release notes to add firewall item back.
SYSGEN_FIREWALL Is Not in the Catalog
To add the Firewall Service (SYSGEN_FIREWALL) to an OS design, you must do one of the following:
- Set the SYSGEN_FIREWALL variable at the command line.
- When you use the OS Design Wizard to create an OS design founded on the Custom Device design template, select Sample Firewall Service.
Also check this thread.