Tracing does not work on HTTPRoutes with matching conditions

[sjberman]

Describe the bug
When using HTTPRoutes with matching conditions like headers, method, or queryParams, traffic is redirected from the external location to an internal location. Tracing does not work on this internal location. Traces must be initialized from the parent location.

To Reproduce

1. Create an HTTPRoute with matching conditions
2. Attach an ObservabilityPolicy to that Route

Additional context
NJS should help with creating a dynamic variable to start tracing depending on the incoming request.

[kate-osborn]

Closing in favor of: #2308