Hi Ramana4111,
There is a GCP service that would be similar to AWS AppConfig. The service is called Resource monitoring and the Google Cloud Product is Cloud Asset Inventory. It can be used to View, monitor, and analyze all your Google Cloud and Anthos assets across projects and services using this metadata inventory service.
This article might also help you check out other GCP products:
https://cloud.google.com/free/docs/aws-azure-gcp-service-comparison
https://cloud.google.com/asset-inventory/docs/overview