KeyMint VTS: add missing purpose/algo

Test was producing an invalid set of parameters in a different way than
intended.

Bug: 197222749
Test: VtsAidlKeyMintTargetTest
Merged-In: I07f706fec81d91e8eee9c0561428142559c54f12
Change-Id: I07f706fec81d91e8eee9c0561428142559c54f12
Ignore-AOSP-First: this is a manual cross-merge
diff --git a/security/keymint/aidl/vts/functional/KeyMintTest.cpp b/security/keymint/aidl/vts/functional/KeyMintTest.cpp
index 9797e0e..2a0ee7f 100644
--- a/security/keymint/aidl/vts/functional/KeyMintTest.cpp
+++ b/security/keymint/aidl/vts/functional/KeyMintTest.cpp
@@ -1841,12 +1841,13 @@
     if (SecLevel() == SecurityLevel::STRONGBOX) return;
 
     auto result = GenerateKey(AuthorizationSetBuilder()
+                                      .Authorization(TAG_ALGORITHM, Algorithm::EC)
                                       .Authorization(TAG_KEY_SIZE, 224)
                                       .Authorization(TAG_EC_CURVE, EcCurve::P_256)
+                                      .SigningKey()
                                       .Digest(Digest::NONE)
                                       .SetDefaultValidity());
-    ASSERT_TRUE(result == ErrorCode::INVALID_ARGUMENT ||
-                result == ErrorCode::UNSUPPORTED_ALGORITHM);
+    ASSERT_TRUE(result == ErrorCode::INVALID_ARGUMENT);
 }
 
 /*