fix: configure alb/gateway health check from liveness_probe with defaults

What

Configures ALB (EKS) and Gateway (GKE) health checks using the service's spec.liveness_probe configuration. This enables native load balancer health checking aligned with Kubernetes liveness probe settings.

Why

Health check parameters (interval, timeout, healthy/unhealthy thresholds) are automatically derived from the service's liveness probe configuration

Links to relevant issues

Related issue: team#621 (closed)