Mark wpt/fetch/metadata/generated/form-submission.https.sub.html as slow

This is a speculative fix for the flakiness.

Bug: 1327081
Change-Id: I5966178a861ffa7ec7b923d70f88646b3bf335a4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3653345
Reviewed-by: Yoichi Osato <yoichio@chromium.org>
Commit-Queue: Yoichi Osato <yoichio@chromium.org>
Auto-Submit: Yutaka Hirano <yhirano@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1005535}
diff --git a/fetch/metadata/generated/form-submission.https.sub.html b/fetch/metadata/generated/form-submission.https.sub.html
index a0f683a..988b07c 100644
--- a/fetch/metadata/generated/form-submission.https.sub.html
+++ b/fetch/metadata/generated/form-submission.https.sub.html
@@ -7,6 +7,7 @@
 -->
 <html lang="en">
   <meta charset="utf-8">
+  <meta name="timeout" content="long">
   <title>HTTP headers on request for HTML form navigation</title>
   <script src="/resources/testharness.js"></script>
   <script src="/resources/testharnessreport.js"></script>
diff --git a/fetch/metadata/generated/form-submission.sub.html b/fetch/metadata/generated/form-submission.sub.html
index c4a5e2f..f862062 100644
--- a/fetch/metadata/generated/form-submission.sub.html
+++ b/fetch/metadata/generated/form-submission.sub.html
@@ -7,6 +7,7 @@
 -->
 <html lang="en">
   <meta charset="utf-8">
+  <meta name="timeout" content="long">
   <title>HTTP headers on request for HTML form navigation</title>
   <script src="/resources/testharness.js"></script>
   <script src="/resources/testharnessreport.js"></script>
diff --git a/fetch/metadata/tools/templates/form-submission.sub.html b/fetch/metadata/tools/templates/form-submission.sub.html
index cbf7b5c..4c9c8c5 100644
--- a/fetch/metadata/tools/templates/form-submission.sub.html
+++ b/fetch/metadata/tools/templates/form-submission.sub.html
@@ -4,6 +4,7 @@
 -->
 <html lang="en">
   <meta charset="utf-8">
+  <meta name="timeout" content="long">
   <title>HTTP headers on request for HTML form navigation</title>
   <script src="/resources/testharness.js"></script>
   <script src="/resources/testharnessreport.js"></script>