grpc passthrough connection retries configurable

[huzlak]

Version

1.11.x (latest stable)

Is your feature request related to a problem? Please describe.

Basically the flow is:

1. Gloo comes online, configured with ExtAuth to connect to an unavailable grpc Passthrough upstream.
2. Gloo complains about possibly being unable to establish the connection
3. Auth upstream service comes online, grpc is exposed
4. 100 requests over N minutes, sent against Gloo, which goes through grpc auth upstream. 401: extauthz_denied
5. Make small configuration change to AuthConfig to make Gloo’s Envoy’s ExtAuthz grpc client to reconnect to grpc server
6. Connection established
7. requests now working.

Describe the solution you'd like

Have the retry configurable, similar to: https://docs.solo.io/gloo-edge/latest/reference/api/github.com/solo-io/gloo/projects/gloo/api/v1/options/retries/retries.proto.sk/#retrypolicy , I can see adding someting like perTryDelay could also be useful in this scenario.

Describe alternatives you've considered

No response

Additional Context

No response