Log keystore key attestation events using statsd.

This is the third CL on sending keystore logging to statsd.
This creates the logs for key attestation events.
Test: Adding tests for logging is yet to be decided.
Bug: 157664923
Merged-In: I412ac59fd6bb2dbcb380f8579740d02ce2fd8790
Change-Id: I16cac8c4ee950adc330659dcb648052e8b2b41a2
diff --git a/keystore/Android.bp b/keystore/Android.bp
index eb0009f..45b721b 100644
--- a/keystore/Android.bp
+++ b/keystore/Android.bp
@@ -36,6 +36,7 @@
         "grant_store.cpp",
         "key_creation_log_handler.cpp",
         "key_operation_log_handler.cpp",
+        "key_attestation_log_handler.cpp",
         "key_store_service.cpp",
         "keyblob_utils.cpp",
         "keymaster_enforcement.cpp",