update google auth library

[lavanyachennupati]

We are using this ffwd shim as a sidecar container for pods running in GKE to publish metrics.
When enabling workload identity on GKE clusters, we noticed all the applications that depend on “google-auth-library-credentials” version < 0.16.2 fail to run with errors

com.google.auth.oauth2.ComputeEngineCredentials runningOnComputeEngine
INFO: Failed to detect whether we are running on Google Compute Engine.
com.google.api.client.http.HttpResponseException: 403 Forbidden
GKE Metadata Server encountered an error: Missing required header "Metadata-Flavor": "Google"

Upgrading the google-auth-library-credentials library used by ffwd shim to
>= v0.16.2 that has the fix to add metadata-flavor header to the requests to metadata server

[lavanyachennupati]

@dmichel1 @hexedpackets @lmuhlha @mattnworb @davidxia @smstone