Merge "Check for null callback pointers in the Vendor HAL AIDL callback util." into main

    ~AidlCallbackHandler() { invalidate(); }

    bool addCallback(const std::shared_ptr<CallbackType>& cb) {

        if (cb == nullptr) {

            LOG(ERROR) << "Unable to register a null callback";

            return false;

        }

        std::unique_lock<std::mutex> lk(callback_handler_lock_);

        void* cbPtr = reinterpret_cast<void*>(cb->asBinder().get());

        const auto& cbPosition = findCbInSet(cbPtr);