Fix URL for Checking out Chromium instructions. am: 73604ccd98 am: 779158afd9

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Virtualization/+/3088065

Change-Id: I942e81b159069673f2d94e480418af7d56c3d78b
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>
diff --git a/docs/custom_vm.md b/docs/custom_vm.md
index b218a5e..57a1b0d 100644
--- a/docs/custom_vm.md
+++ b/docs/custom_vm.md
@@ -39,7 +39,7 @@
 First, check out source code from the ChromiumOS and Chromium projects.
 
 * Checking out ChromiumOS: https://www.chromium.org/chromium-os/developer-library/guides/development/developer-guide/
-* Checking out Chromium: https://g3doc.corp.google.com/chrome/chromeos/system_services_team/dev_instructions/g3doc/setup_checkout.md?cl=headless
+* Checking out Chromium: https://g3doc.corp.google.com/chrome/chromeos/system_services_team/dev_instructions/g3doc/setup_checkout.md?cl=head
 
 Important: When you are at the step “Set up gclient args” in the Chromium checkout instruction, configure .gclient as follows.