router: add missing unit tests for x-envoy-attempt-count on upstream requests (#10368)
router: add missing unit tests for x-envoy-attempt-count on upstream requests (#10368)

Description: adding missing unit test coverage.
Risk Level: low
Testing: added new tests

Fixes #10366

Signed-off-by: Jose Nino <ca94e32c82b10963d0ce6eadf427a615ff7d1c0b@lyft.com>
envoyproxy/envoy-wasm,envoyproxy/envoy,envoyproxy/envoy,lyft/envoy,istio/envoy,envoyproxy/envoy,lyft/envoy,istio/envoy,lizan/envoy,lizan/envoy,envoyproxy/envoy,envoyproxy/envoy,envoyproxy/envoy-wasm,lyft/envoy,lizan/envoy,envoyproxy/envoy,istio/envoy,istio/envoy,envoyproxy/envoy-wasm,envoyproxy/envoy,envoyproxy/envoy,lyft/envoy,lizan/envoy,envoyproxy/envoy-wasm,envoyproxy/envoy-wasm,envoyproxy/envoy-wasm,lizan/envoy,istio/envoy,envoyproxy/envoy,envoyproxy/envoy-wasm,envoyproxy/envoy,lyft/envoy,istio/envoy,lizan/envoy,istio/envoy,envoyproxy/envoy,lyft/envoy,envoyproxy/envoy