Add FileChooserChromeOs for Chrome Remote Desktop (CRD) File Transfer

Provides a file selection dialog on the host device during a CRD
session. This allows user to select file on the host device for file
transfer to the requesting local device.

Screen grab for ui dialog on host device:
http://screen/3sQ6KKNWh2554LL

Bug: b/282910533
Change-Id: I44fb13ea0c84ed933a59ddbde5a1809b183c30d4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4577197
Reviewed-by: Scott Violet <sky@chromium.org>
Reviewed-by: Joe Downing <joedow@chromium.org>
Reviewed-by: Ben Franz <bfranz@chromium.org>
Commit-Queue: Ashutosh Singhal <macinashutosh@google.com>
Reviewed-by: Roland Bock <rbock@google.com>
Cr-Commit-Position: refs/heads/main@{#1155486}