KeyMint: don't mix Binder and std shared pointers

Bug: 203871378
Test: VtsAidlKeyMintTargetTest, TreeHugger
Change-Id: I8671342939af2bbdef643be9ce81b0bb9e7ae1a9
diff --git a/trusty/keymaster/keymint/service.cpp b/trusty/keymaster/keymint/service.cpp
index 4060278..d5a77fb 100644
--- a/trusty/keymaster/keymint/service.cpp
+++ b/trusty/keymaster/keymint/service.cpp
@@ -31,7 +31,7 @@
 
 template <typename T, class... Args>
 std::shared_ptr<T> addService(Args&&... args) {
-    std::shared_ptr<T> service = std::make_shared<T>(std::forward<Args>(args)...);
+    std::shared_ptr<T> service = ndk::SharedRefBase::make<T>(std::forward<Args>(args)...);
     auto instanceName = std::string(T::descriptor) + "/default";
     LOG(ERROR) << "Adding service instance: " << instanceName;
     auto status = AServiceManager_addService(service->asBinder().get(), instanceName.c_str());