Add westworld logging to signed config.

This will allow verification of how well the feature works in prod, as
well as tracking real time usage once Q is released.

Test: atest CtsSignedConfigHostTests
Test: ./out/host/linux-x86/bin/statsd_testdrive 123

Bug: 110509075
Bug: 122350327
Change-Id: Ibada9490e18cbeee74e18aaa93ba9d0d7d03845e