KeyMint VTS: local asymmetric verification

Change verification of ECDSA and RSA signatures so it happens locally
in the test, rather than by invoking a VERIFY operation against KeyMint.

Test: VtsAidlKeyMintTargetTest
Change-Id: I0efc30f3c96cd70ac636d34718eff53cc23f1480
diff --git a/security/keymint/aidl/vts/functional/KeyMintAidlTestBase.h b/security/keymint/aidl/vts/functional/KeyMintAidlTestBase.h
index cb38938..1a14d47 100644
--- a/security/keymint/aidl/vts/functional/KeyMintAidlTestBase.h
+++ b/security/keymint/aidl/vts/functional/KeyMintAidlTestBase.h
@@ -162,6 +162,8 @@
                        const string& signature, const AuthorizationSet& params);
     void VerifyMessage(const string& message, const string& signature,
                        const AuthorizationSet& params);
+    void LocalVerifyMessage(const string& message, const string& signature,
+                            const AuthorizationSet& params);
 
     string EncryptMessage(const vector<uint8_t>& key_blob, const string& message,
                           const AuthorizationSet& in_params, AuthorizationSet* out_params);