Support discovering system policy according to the drop reason

[seungsoo-lee]

Basically, knoxAutoPolicy discovers the system policy based on the system log/alert.

Also, we need to support the functionality that can discover the system policy from the dropped system log as well.

There can be some types of drop reasons.

• there is no matched policy.

• there is a deny policy.

• [ ] We should provide a configuration that how much cover the dropped system log: no matched only / all dropped logs