terraform-google-modules/terraform-google-kubernetes-engine

AI Summary: The task is to debug and fix a Terraform module for Google Kubernetes Engine (GKE) cluster configuration. The module is failing due to a `coalesce` function error when `node_pools_linux_node_configs_sysctls` is set without also defining `node_pools_cgroup_mode`. The solution involves modifying the module's code to handle cases where `node_pools_cgroup_mode` is not explicitly defined, ensuring the `coalesce` function always has at least one non-null, non-empty-string argument.