Add USB control commands to CrostiniManager

This CL allows users of CrostiniManager to add, remove, and list USB
devices attached to a vm. This will ultimately allow USB devices to be
shared with Crostini using the UI.

Bug: 891381
Change-Id: Id81ca37348df5b57c69a76d7f6123cdfac6ec685
Commit-Queue: Fergus Dall <>
Reviewed-by: Steven Bennetts <>
Reviewed-by: Nicholas Verne <>
Reviewed-by: Dominick Ng <>
Reviewed-by: Reilly Grant <>
Cr-Commit-Position: refs/heads/master@{#620630}
16 files changed