init: add some documentation in service_utils.h

    Descriptor(const std::string& name, android::base::unique_fd fd)

    Descriptor(const std::string& name, android::base::unique_fd fd)

        : name_(name), fd_(std::move(fd)){};

        : name_(name), fd_(std::move(fd)){};

    // Publish() unsets FD_CLOEXEC from the FD and publishes its name via setenv().  It should be

    // called when starting a service after fork() and before exec().

    void Publish() const;

    void Publish() const;

  private:

  private:

    std::string context;

    std::string context;

    bool passcred = false;

    bool passcred = false;

    // Create() creates the named unix domain socket in /dev/socket and returns a Descriptor object.

    // It should be called when starting a service, before calling fork(), such that the socket is

    // synchronously created before starting any other services, which may depend on it.

    Result<Descriptor> Create(const std::string& global_context) const;

    Result<Descriptor> Create(const std::string& global_context) const;

};

};