Add support for keystore2 storage metrics

Add pull atoms for getting information about current state of keystore2
storage.

Bug: 172013262
Test: atest system/keystore/keystore2
Test: statsd_testdrive 10103
Change-Id: I0ee115d9bc65d17e6533c4520a1b65067cd2260c
diff --git a/keystore2/Android.bp b/keystore2/Android.bp
index af177be..dfc1db0 100644
--- a/keystore2/Android.bp
+++ b/keystore2/Android.bp
@@ -54,6 +54,8 @@
         "librand",
         "librusqlite",
         "libstatslog_rust",
+        "libstatslog_rust_header",
+        "libstatspull_rust",
         "libthiserror",
     ],
     shared_libs: [