Telemetry doesn't work with non-ADC

[enocom]

If I launch the Proxy with an OAuth2 token or a credentials file while using Telemetry, the Proxy fails to start.

The reason for this is stackdriver does requires that we set non-ADC in the stackdriver.Options struct:

https://github.com/GoogleCloudPlatform/alloydb-auth-proxy/blob/5d496b4ad4310436f609894bae19c89a0b90f4a5/cmd/root.go#L980-L983

In addition, the Proxy should love the error as we've disabled error reporting after parsing the config.