conformance: always check `ResolvedRefs` condition in `Gateway` conformance tests

[mlavacca]

What would you like to be added:

In the Gateway conformance tests, the ListenerConditionResolvedRefs is checked only in those tests expecting it to have statusfalse (e.g., GatewaySecretMissingReferenceGrant, GatewaySecretInvalidReferenceGrant, ...), but it is never checked in those tests who expect the routing to be successful. This leads to never checking the ResolvedRefs reason with ConditionStatus == true.

Why this is needed:

This is needed to ensure that the ListenerConditionResolvedRefs is always set, no matter if the ConditionStatus is true, or false.

[nathancoleman]

There was some relevant discussion between myself, @skriss and @robscott in #1158 (comment). The spec doesn't specifically call for this to be set to true for a healthy state today. This issue is probably the best venue for deciding what we want to do.

[mlavacca]

@youngnick @shaneutt Reading from the GEP #1383 that has recently merged, I see that has been decided to always enforce the Gateway conditions, even when true. Do you think I can pick this one and start implementing it?

[shaneutt]

I would say yes, but I'll defer to @youngnick since he has more context on this than I.

[mlavacca]

ping @youngnick

[youngnick]

Ah, sorry about this one, missed it. Yes please @mlavacca, please start working on this one.