[sdk-platform-java] ServiceManager's HttpJson Tests fails for IAM RPC Callables

Error:
```
2023-07-10T15:19:26.5433019Z 15:19:26:539 [ERROR] Errors:
2023-07-10T15:19:26.5436045Z 15:19:26:539 [ERROR] ServiceManagerClientHttpJsonTest.getIamPolicyTest:900 » NotFound com.google.api.client.http.HttpResponseException: 404
2023-07-10T15:19:26.5437373Z POST https://servicemanagement.googleapis.com:443/v1/GetIamPolicyRequest-1527610370:getIamPolicy?$alt=json;enum-encoding%3Dint
2023-07-10T15:19:26.5438254Z Method not found for path 'https:///v1/GetIamPolicyRequest-1527610370:getIamPolicy'
2023-07-10T15:19:26.5439405Z 15:19:26:539 [ERROR] ServiceManagerClientHttpJsonTest.setIamPolicyTest:844 » NotFound com.google.api.client.http.HttpResponseException: 404
2023-07-10T15:19:26.5440341Z POST https://servicemanagement.googleapis.com:443/v1/SetIamPolicyRequest1223629066:setIamPolicy?$alt=json;enum-encoding%3Dint
2023-07-10T15:19:26.5441076Z Method not found for path 'https:///v1/SetIamPolicyRequest1223629066:setIamPolicy'
2023-07-10T15:19:26.5441895Z 15:19:26:539 [ERROR] ServiceManagerClientHttpJsonTest.testIamPermissionsTest:950 » NotFound com.google.api.client.http.HttpResponseException: 404
2023-07-10T15:19:26.5442821Z POST https://servicemanagement.googleapis.com:443/v1/TestIamPermissionsRequest942398222:testIamPermissions?$alt=json;enum-encoding%3Dint
2023-07-10T15:19:26.5443539Z Method not found for path 'https:///v1/TestIamPermissionsRequest942398222:testIamPermissions'
```

Seen in: https://github.com/googleapis/google-cloud-java/pull/9583

This might be due to a mismatch between the IAM Request's Resource and IAM callable's path. Might be a generator or proto issue, but will need to be debugged.