chore: add default_version and codeowner_team to .repo-metadata.json (#402)

* chore: add default_version and codeowner_team to .repo-metadata.json

* update codeowner_team

Author: parthea

.repo-metadata.json

@@ -9,5 +9,7 @@
     "library_type": "INTEGRATION",
     "repo": "googleapis/python-bigquery-pandas",
     "distribution_name": "pandas-gbq",
-    "api_id": "bigquery.googleapis.com"
-  }
+    "api_id": "bigquery.googleapis.com",
+    "default_version": "",
+    "codeowner_team": "@googleapis/api-bigquery"
+}