[Output Only] The state of the subnetwork, which can be one of the
following values: READY: Subnetwork is created and ready to use
DRAINING: only applicable to subnetworks that have the purpose set
to INTERNAL_HTTPS_LOAD_BALANCER and indicates that connections to
the load balancer are being drained. A subnetwork that is draining
cannot be used or modified until it reaches a status of READY
Values:
UNDEFINED_STATE (0):
A value indicating that the enum field is not
set.
DRAINING (480455402):
Subnetwork is being drained.
READY (77848963):
Subnetwork is ready for use.