Merge "health impl: compare interfaces with their binders" am: 1f5c57c9

    std::lock_guard<decltype(callbacks_lock_)> lock(callbacks_lock_);

    auto matches = [callback](const auto& linked) {

        return linked->callback() == callback;  // compares shared_ptr

        return linked->callback()->asBinder() == callback->asBinder();  // compares binder object

    };

    auto it = std::remove_if(callbacks_.begin(), callbacks_.end(), matches);

    bool removed = (it != callbacks_.end());