[flake] Increase timeout to fix h2_test flakiness (#37767)

In some rare occasions on Win machines (0,2-0,5%), the tests are stuck before the handshake when we execute `grpc_call_start_batch`. We receive OP_COMPLETE with `Deadline Exceeded {grpc_status:4}` for such cases. The PR bumps it from 5 to 30s (no flakes for --runs_per_test=1000).

Closes #37767

COPYBARA_INTEGRATE_REVIEW=https://github.com/grpc/grpc/pull/37767 from erm-g:h2test 9d1208ee1f
PiperOrigin-RevId: 676531975

test/core/end2end/h2_ssl_cert_test.cc

@@ -42,6 +42,7 @@
 
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/config/config_vars.h"
+#include "src/core/lib/gprpp/time.h"
 #include "src/core/util/tmpfile.h"
 #include "test/core/end2end/cq_verifier.h"
 #include "test/core/end2end/data/ssl_test_data.h"
@@ -196,7 +197,7 @@ static CoreTestConfigWrapper configs[] = {
 static void simple_request_body(grpc_core::CoreTestFixture* f,
                                 test_result expected_result) {
   grpc_call* c;
-  gpr_timespec deadline = grpc_timeout_seconds_to_deadline(5);
+  gpr_timespec deadline = grpc_timeout_seconds_to_deadline(30);
   grpc_completion_queue* cq = grpc_completion_queue_create_for_next(nullptr);
   grpc_core::CqVerifier cqv(cq);
   grpc_op ops[6];
@@ -226,13 +227,13 @@ static void simple_request_body(grpc_core::CoreTestFixture* f,
   CHECK_EQ(error, GRPC_CALL_OK);
 
   cqv.Expect(grpc_core::CqVerifier::tag(1), expected_result == SUCCESS);
-  cqv.Verify();
+  cqv.Verify(grpc_core::Duration::Seconds(60));
 
   grpc_call_unref(c);
   grpc_channel_destroy(client);
   grpc_server_shutdown_and_notify(server, cq, nullptr);
   cqv.Expect(nullptr, true);
-  cqv.Verify();
+  cqv.Verify(grpc_core::Duration::Seconds(60));
   grpc_server_destroy(server);
   grpc_completion_queue_shutdown(cq);
   CHECK(grpc_completion_queue_next(cq, gpr_inf_future(GPR_CLOCK_REALTIME),