A network engineer is configuring a GRE over IPsec tunnel from an on-premises Cisco IOS XE router to a Google Cloud HA VPN gateway that terminates a native (non-Cisco) endpoint. The engineer wants to protect the GRE tunnel with IPsec and dynamically exchange routes over the overlay. When reviewing the design, the team lead notes that the chosen Google Cloud HA VPN gateway does not support GRE encapsulation at all. What is the correct action to establish encrypted, routed connectivity to this native Google Cloud endpoint?