Increase test coverage

The VTS Gatekeeper tests never triggered a case where
GateKeeper::DoVerify() failed, so add a test that does that.

Bug: 160731903
Test: run test with instrumented build
Change-Id: Ibcc51371e496f893c18ed9e8cdc53dfef8f4e4ad
diff --git a/gatekeeper/1.0/vts/functional/VtsHalGatekeeperV1_0TargetTest.cpp b/gatekeeper/1.0/vts/functional/VtsHalGatekeeperV1_0TargetTest.cpp
index 7d32ced..618624e 100644
--- a/gatekeeper/1.0/vts/functional/VtsHalGatekeeperV1_0TargetTest.cpp
+++ b/gatekeeper/1.0/vts/functional/VtsHalGatekeeperV1_0TargetTest.cpp
@@ -236,6 +236,10 @@
   generatePassword(password, 0);
   enrollNewPassword(password, enrollRsp, true);
   verifyPassword(password, enrollRsp.data, 1, verifyRsp, true);
+
+  ALOGI("Testing unenrolled password doesn't verify");
+  generatePassword(password, 1);
+  verifyPassword(password, enrollRsp.data, 1, verifyRsp, false);
   ALOGI("Testing Enroll+Verify done");
 }