feat: promote to 1.0.0 (#764)

Co-authored-by: Manu Menzella <menzella@google.com>
Co-authored-by: Tianzi Cai <tianzi@google.com>

.repo-metadata.json

@@ -4,7 +4,7 @@
   "product_documentation": "https://cloud.google.com/pubsub/lite/docs",
   "api_description": "is designed to provide reliable,\nmany-to-many, asynchronous messaging between applications. Publisher\napplications can send messages to a topic and other applications can\nsubscribe to that topic to receive the messages. By decoupling senders and\nreceivers, Google Cloud Pub/Sub allows developers to communicate between\nindependently written applications.\n\nCompared to Google Pub/Sub, Pub/Sub Lite provides partitioned zonal data\nstorage with predefined capacity. Both products present a similar API, but\nPub/Sub Lite has more usage caveats.\n\nSee the [Google Pub/Sub Lite docs](https://cloud.google.com/pubsub/quickstart-console#before-you-begin) for more details on how to activate\nPub/Sub Lite for your project, as well as guidance on how to choose between\nCloud Pub/Sub and Pub/Sub Lite.",
   "client_documentation": "https://googleapis.dev/java/google-cloud-pubsublite/latest/index.html",
-  "release_level": "beta",
+  "release_level": "ga",
   "transport": "grpc",
   "requires_billing": true,
   "language": "java",