search for AVCs only, ignore USER_AVCs
    
    Because the test uses a custom policy module, there will always
    be at least 2 USER_AVC messages reported (received policyload notice
    caused by insertion and removal of the policy module). The ausearch
    calls should only care about AVC messages.
    The test also uses the semanage command, which is not required in Makefile.
    Both issues are now fixed.