CrOS FilesApp: Comments and test to disallow sharing DriveFS .Trash with crostini

Bug: 878324
Change-Id: I2eaec453ff0555b6a77c8dd650a705f8be2d89bd
Reviewed-on: https://chromium-review.googlesource.com/c/1300818
Reviewed-by: Timothy Loh <timloh@chromium.org>
Reviewed-by: Sam McNally <sammc@chromium.org>
Commit-Queue: Joel Hockey <joelhockey@chromium.org>
Cr-Commit-Position: refs/heads/master@{#603000}
2 files changed