Merge http2 integration test case into grpc case

test/integration/connect/envoy/case-grpc/verify.bats

@@ -10,6 +10,14 @@ load helpers
   retry_default curl -f -s localhost:19001/stats -o /dev/null
 }
 
+@test "s1 proxy listener should be up and have right cert" {
+  assert_proxy_presents_cert_uri localhost:21000 s1
+}
+
+@test "s2 proxy listener should be up and have right cert" {
+  assert_proxy_presents_cert_uri localhost:21001 s2
+}
+
 @test "s2 proxy should be healthy" {
   assert_service_has_healthy_instances s2 1
 }
@@ -20,6 +28,7 @@ load helpers
 }
 
 @test "s1 upstream should be able to connect to s2 via grpc" {
+  # This test also covers http2 since gRPC always uses http2
   run fortio grpcping localhost:5000
 
   echo "OUTPUT: $output"