test: fix http2_upstream_integration_test flakiness on Windows (#14497)
test: fix http2_upstream_integration_test flakiness on Windows (#14497)

Signed-off-by: Randy Miller <6562099ead040473f96ba0a5b0bedb01c614b31b@gmail.com>
lyft/envoy,envoyproxy/envoy,envoyproxy/envoy,lyft/envoy,envoyproxy/envoy,envoyproxy/envoy,envoyproxy/envoy,envoyproxy/envoy,lyft/envoy,lyft/envoy,envoyproxy/envoy,envoyproxy/envoy,lyft/envoy,envoyproxy/envoy,envoyproxy/envoy,lyft/envoy,envoyproxy/envoy,envoyproxy/envoy