test: Enable test sharding for //test/common/http:conn_manager_impl_test (#12865)
test: Enable test sharding for //test/common/http:conn_manager_impl_test (#12865)

Test runtime in CI under config clang-tsan is dangerously close to the 300sec timeout.

Signed-off-by: Antonio Vicente <3264b79815f9dfda4d4b4e4281b8e33e1075040b@google.com>
lyft/envoy,envoyproxy/envoy,envoyproxy/envoy,envoyproxy/envoy-wasm,envoyproxy/envoy,envoyproxy/envoy-wasm,lyft/envoy,envoyproxy/envoy-wasm,lyft/envoy,envoyproxy/envoy,envoyproxy/envoy-wasm,envoyproxy/envoy-wasm,lyft/envoy,envoyproxy/envoy,envoyproxy/envoy,envoyproxy/envoy-wasm,envoyproxy/envoy,envoyproxy/envoy,envoyproxy/envoy,lyft/envoy,lyft/envoy,envoyproxy/envoy-wasm,envoyproxy/envoy,envoyproxy/envoy,envoyproxy/envoy