If unspecified, INGRESS_TRAFFIC_ALLOWED_ALL will be used.
Values:
INGRESS_TRAFFIC_ALLOWED_UNSPECIFIED (0):
Unspecified
INGRESS_TRAFFIC_ALLOWED_ALL (1):
Allow HTTP traffic from public and private
sources.
INGRESS_TRAFFIC_ALLOWED_INTERNAL_ONLY (2):
Allow HTTP traffic from only private VPC
sources.
INGRESS_TRAFFIC_ALLOWED_INTERNAL_AND_LB (3):
Allow HTTP traffic from private VPC sources
and through load balancers.