Implement keystore2 logging of key creation events.

This CL implements logging of key creation events via statsd.

Bug: 172013262
Test: enable keystore2 on cuttlfish, run cts tests for key generation,
run the test drive script provided by statsd and observe the logs
created.

Change-Id: Ib60ed356ce809d27f7625ab0743a9300c454f1c8
diff --git a/keystore2/Android.bp b/keystore2/Android.bp
index c69774d..f4253bc 100644
--- a/keystore2/Android.bp
+++ b/keystore2/Android.bp
@@ -52,6 +52,7 @@
         "liblog_rust",
         "librand",
         "librusqlite",
+        "libstatslog_rust",
         "libthiserror",
     ],
 }