updater-start will update system and sign its files.
Kernel will also be updated
integrity-applier is only sign files of current system
Do not forget to put policy to /etc/integrity/policy
for integrity to be enforced.
Working example of policy is in /usr/share/doc/ima-evm-integrity-check*/policy.example
updater-start  will run scripts from /etc/updater.d with argument "apply" after packages
install and with argument "remove" before packages install
