[iOS] Change pipes to backticks in /ios/chrome/browser/https_upgrades

Please review the CL to ensure that nothing is broken and the script
didn't miss some pipes.

This should allow us to have a better formatting in Xcode.

This CL was uploaded by git cl split.

Bug: 1311955
Change-Id: I5ce7024e22496a84d669fb67eba8dc9e1f9aba0e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3842175


Auto-Submit: Gauthier Ambard <gambard@chromium.org>
Commit-Queue: Gauthier Ambard <gambard@chromium.org>
Reviewed-by: Sylvain Defresne <sdefresne@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1040899}