feat: promote to 1.0.0 (#205)

Release-As: 1.0.0

Author: stephaniewang526

.repo-metadata.json

@@ -4,7 +4,7 @@
   "product_documentation": "https://cloud.google.com/bigquery/docs/reference/bigqueryconnection/rest",
   "api_description": "allows users to manage BigQuery connections to external data sources.",
   "client_documentation": "https://cloud.google.com/bigquery/docs/reference/reservations/rpc/google.cloud.bigquery.reservation.v1beta1",
-  "release_level": "beta",
+  "release_level": "ga",
   "transport": "grpc",
   "language": "java",
   "repo": "googleapis/java-bigqueryconnection",