UploadFile: allow ancillary files

Currently UploadFile is restricted to a static set of files, and thus
gnt-cluster redist-conf (silently) fails to upload all config files.
With this patch we add the new static files we distribute, and all
hypervisor-provided ancillary files.

Signed-off-by: Guido Trotter <ultrotter@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>