[perf] add extra comment to liveness handler to explain ordering

This CL is a follow up to
https://skia-review.googlesource.com/c/buildbot/+/895268

Bug: b/361129890
Change-Id: Ide4776625d4f54c85d56d9c58ab634069a36497a
Reviewed-on: https://skia-review.googlesource.com/c/buildbot/+/895996
Reviewed-by: Kaylee Lubick <kjlubick@google.com>
Commit-Queue: Leina Sun <sunxiaodi@google.com>
Auto-Submit: Leina Sun <sunxiaodi@google.com>
diff --git a/perf/go/frontend/frontend.go b/perf/go/frontend/frontend.go
index 2819040..481ca41 100644
--- a/perf/go/frontend/frontend.go
+++ b/perf/go/frontend/frontend.go
@@ -947,6 +947,9 @@
 	h = httputils.LoggingGzipRequestResponse(h)
 	if !f.flags.Local {
 		h = httputils.HealthzAndHTTPS(h)
+		// add liveness handler after https routing since these are applied in
+		// reverse order to ensure k8 pod can access the endpoint without
+		// 301 moved permanently status
 		h = f.liveness(h)
 	}
 	http.Handle("/", h)