updater: Fix IntegrationTest.OfflineInstall fails Medium with UAC on

FIXED: 41487742
Change-Id: I91bed6b442f6c072c2a492b7c5f106220ce9da86
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5406301


Commit-Queue: S Ganesh <ganesh@chromium.org>
Auto-Submit: S Ganesh <ganesh@chromium.org>
Reviewed-by: Xiaoling Bao <xiaolingbao@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1280049}