Remove ipv4.endpoint.address
Remove ipv4.endpoint.address

This field was added in the intial implementation, before Route existed
to pass the local and remote addresses to the packet-writing path.
Today, the Route's members should be respected. A similar bug was
previously fixed in 214650822.

PiperOrigin-RevId: 219474095
Change-Id: Id2a8ee4421d2841c8d88ccb3c193c455086350ee

google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor