chore: update repo-metadata.json client_documentation link (#240)

* chore: updating doc link

* chore: fix missing comma

Author: eaball35

.repo-metadata.json

@@ -3,7 +3,7 @@
   "name_pretty": "Common Protos",
   "product_documentation": "n/a",
   "api_description": "n/a",
-  "client_documentation": "https://googleapis.dev/java/proto-google-common-protos/latest/index.html",
+  "client_documentation": "https://cloud.google.com/java/docs/reference/proto-google-common-protos/latest/history",
   "release_level": "ga",
   "transport": "grpc",
   "requires_billing": true,