Merge "Make PrivateDnsDohTest.SessionResumption more robust against flag reset"

TEST_F(PrivateDnsDohTest, SessionResumption) {

    const int initial_max_idle_timeout_ms = 1000;

    for (const auto& flag : {"0", "1"}) {

        SCOPED_TRACE(fmt::format("flag: {}", flag));

        auto sp = make_unique<ScopedSystemProperties>(kDohSessionResumptionFlag, flag);

        // Each loop takes around 3 seconds, if the system property "doh" is reset in the middle

        // of the first loop, this test will fail when running the second loop because DnsResolver

        // updates its "doh" flag when resetNetwork() is called. Therefore, add another

        // ScopedSystemProperties for "doh" to make the test more robust.

        auto sp2 = make_unique<ScopedSystemProperties>(kDohFlag, "1");

        resetNetwork();

        ASSERT_TRUE(doh.stopServer());