GitLab

Add log warning messages when lacros-chrome didn't launch because:
- The session is not yet active (for instance when using
  "Browse as a Guest")
- The current user is not allowed
- Lacros is not supported or allowed

Bug: None
Change-Id: I06a60daace575a32b46662be36c5ae824a4ea744
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2583622
Commit-Queue: Pilar Molina Lopez <pmolinalopez@google.com>
Reviewed-by: Hidehiko Abe <hidehiko@chromium.org>
Cr-Commit-Position: refs/heads/master@{#836175}