Issue
Any rbac user having eventing_manage_functions role with no data privileges is attached is unable to modify function settings for any given handler.

steps to reproduce

1. Create eventing handler abcd using full admin role.

2. Create rbac user user1 having following role.

3. Login as user1.

4. User is unable to modify function settings, save button is disabled.

5. No such issues observed in REST.

6. Add following data privileges for user1 in addition to manage scope functions role.

7. Login as user1, user is able to modify and save function settings.