chore: update repo-metadata.json client_documentation link (#213)

* chore: updating doc link * chore: fix missing comma

Author: eaball35

.repo-metadata.json

@@ -3,7 +3,7 @@
  "name_pretty": "IAM",
  "product_documentation": "n/a",
  "api_description": "n/a",
- "client_documentation": "https://googleapis.dev/java/proto-google-iam-v1/latest/index.html",
+ "client_documentation": "https://cloud.google.com/java/docs/reference/proto-google-iam-v1/latest/history",
  "release_level": "ga",
  "transport": "grpc",
  "requires_billing": true,