condition for the ready state

[wasaga]

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

When a new replica pod spins up, it would start serving traffic once reported as ready.

However it takes some time to fetch the configuration from the databroker, apply it to the XDS and it become available.

Describe the solution you'd like

We should adjust pod readiness to until after the configuration has been fetched and applied.

Describe alternatives you've considered

Explain any additional use-cases

If there are any use-cases that would help us understand the use/need/value please share them as they can help us decide on acceptance and prioritization.

Additional context

Add any other context or screenshots about the feature request here.

[wasaga]

Related: pomerium/pomerium#4313