I've successfully built a route-based tunnel between a Cisco ISRG2 and CheckPoint R80.30 gateway in GCP. Both sides are using IKEv1 with the default lifetimes of 1 day for Phase 1 and 1 hour for Phase 2.
Unfortunately, the tunnel stops passing traffic after it's been up for an hour. Here's the relevant IPSec configuration on the Cisco (the default lifetime is 3600 seconds, so it doesn't show up in the configuration):
crypto ipsec transform-set ESP_AES128_SHA esp-aes esp-sha-hmac
mode tunnel
crypto ipsec profile CHECKPOINT_IKEV1
set security-association lifetime kilobytes disable
set transform-set ESP_AES128_SHA