test: add failing assertion to flaky swift test and ignore it (#1683)
test: add failing assertion to flaky swift test and ignore it (#1683)

Signed-off-by: Snow Pettersen <18824beaba694b0802bee531b635db27ba08e6bb@lyft.com>

Adds an assertion that we don't get a cancel callback, which fails consistently locally. Ignore the test
until we can fix the underlying issue

Description:
Risk Level: Low
Testing: n/a
Docs Changes: n/a
Release Notes: n/a

envoyproxy/envoy-mobile,envoyproxy/envoy-mobile,envoyproxy/envoy-mobile,envoyproxy/envoy-mobile,envoyproxy/envoy-mobile,envoyproxy/envoy-mobile,envoyproxy/envoy-mobile,envoyproxy/envoy-mobile,envoyproxy/envoy-mobile