Cert: Add interface to PySecurity/CertSecurity

wait_for_enforce_security_event(expected_event)

This interface will allow the caller to wait for a callback
result from enforcing security policy over the facade.

Bug: 145638034
Test: cert/run SecurityTest:test_dut_initiated_no_input_no_output_no_input_no_output_twice_same_acl --host --gotta-go-fast --verbose
Tag: #gd-refactor
Change-Id: Iea4156e399afb09944f3e12229b45346c873f6aa