chromeos-installer: Add IUSE for lvm_stateful_partition

Use the lvm stateful mode for chromeos-install if the USE flag
is enabled.

BUG=b:172344853
TEST=emerge chromeos-installer; check /usr/sbin/chromeos-install

Cq-Depend: chromium:2434286
Change-Id: Ia9e92a87d0c76a84d359544c832b834dcd8d2b70
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/overlays/chromiumos-overlay/+/2565299
Tested-by: Sarthak Kukreti <sarthakkukreti@chromium.org>
Commit-Queue: Sarthak Kukreti <sarthakkukreti@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
1 file changed