[UPMAccessLossWarning] Show the sheet on startup

The access loss warning sheet is shown on Chrome startup.

The change of the ChromePasswordManagerClient is hard to test
because it would be necessary to create the bridge every time client
is created and then pass it to the client so a mock could be used in
tests. The bridge should then only be created for Android, which would
further complicate the change.

Bug: 353283669
Change-Id: Ifc28ea150a8153ea84254f2b9b51c24740157ce5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5823412
Auto-Submit: Ivana Žužić <izuzic@google.com>
Reviewed-by: Ioana Pandele <ioanap@chromium.org>
Commit-Queue: Ivana Žužić <izuzic@google.com>
Cr-Commit-Position: refs/heads/main@{#1348714}