Remove keybox from OEMCrypto ref

Merge from Widevine repo of http://go/wvgerrit/56526

This CL removes the test keybox from OEMCrypto reference code.

Test: unit tests
Bug: 76393338 split mock into ref and testbed
Change-Id: I4bf0eb777c6851191d0ac9ccf8e2b42c55c8f6b9

libwvdrmengine/oemcrypto/test/oemcrypto_test_android.cpp

@@ -40,6 +40,12 @@ TEST_F(OEMCryptoAndroidLMPTest, GetKeyDataImplemented) {
   }
 }
 
+TEST_F(OEMCryptoAndroidLMPTest, ValidKeybox) {
+  if (OEMCrypto_GetProvisioningMethod() == OEMCrypto_Keybox) {
+    ASSERT_EQ(OEMCrypto_SUCCESS, OEMCrypto_IsKeyboxValid());
+  }
+}
+
 TEST_F(OEMCryptoAndroidLMPTest, MinVersionNumber9) {
   uint32_t version = OEMCrypto_APIVersion();
   ASSERT_LE(9u, version);