[lacros] Update lacros QA qualified version

This CL will update lacros version in //chrome/LACROS_QA_QUALIFIED_VERSION. This
file will be used in Upreving the RootFS-Lacros in the CROS image.

If this CL caused regressions, please revert and pause the autoroller at
https://luci-scheduler.appspot.com/jobs/chrome/lacros-qa-qualified-tracking-roller
Also please file a bug to OS>LaCrOS>Partner, and CC svenzheng@chromium.org.

R=rubber-stamper@appspot.gserviceaccount.com

Change-Id: I860ffff74cfae7c63ff37b380ec3e50ed1e8aea8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4987953
Commit-Queue: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Auto-Submit: lacros-tracking-roller@chops-service-accounts.iam.gserviceaccount.com <lacros-tracking-roller@chops-service-accounts.iam.gserviceaccount.com>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Cr-Commit-Position: refs/branch-heads/6099@{#4}
Cr-Branched-From: e6ee450-refs/heads/main@{#1217362}

chrome/LACROS_QA_QUALIFIED_VERSION

@@ -1,7 +1 @@
-This is a placeholder file to track the latest QA qualified version of Lacros on
-different channels, and it is meant to be consumed by pupr to locate the release
-candidates of RootFS-Lacros and uprev the corresponding ebuild files.
-
-The content of this file is expected to be a plain canonical Chrome version, and
-the file is supposed to be updated in branches automatically by a bot, so please
-do not update it manually unless you know what you're doing.
+120.0.6099.0