gce: temporary add external IPs to instances
gce: temporary add external IPs to instances

There seems to be some issue with DHCP if instance does not have external IP.
Test if it will work with external IP.

dotweiba/syzkaller,google/syzkaller,google/syzkaller,google/syzkaller,xairy/syzkaller,google/syzkaller,hyz0906/syzkaller,hyz0906/syzkaller,xairy/syzkaller,hyz0906/syzkaller,zoulasc/syzkaller,xairy/syzkaller,google/syzkaller,xairy/syzkaller,zoulasc/syzkaller,xairy/syzkaller,xairy/syzkaller,hyz0906/syzkaller,zoulasc/syzkaller,hyz0906/syzkaller,dotweiba/syzkaller,google/syzkaller,zoulasc/syzkaller,xairy/syzkaller,dotweiba/syzkaller,dotweiba/syzkaller,google/syzkaller