factory_install: Correct post install file processing.

The cros_payload command has been changed to support multiple
compression formats and defined 'download' is compressed while 'install'
is uncompressed.

So we have to follow same calling convention in factory installer.

- firmware and complete are already uncompressed in 'cros_payload install'.
- release_image.part1 is compressed so we have to decompress first.

BUG=chromium:711615
TEST=Boots factory install shim and finished installation.

Change-Id: Icf322c64993cfadcb1f3c543be2376081110b409
Reviewed-on: https://chromium-review.googlesource.com/503128
Commit-Ready: Hung-Te Lin <hungte@chromium.org>
Tested-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-by: Pi-Hsun Shih <pihsun@chromium.org>
Reviewed-by: Youcheng Syu <youcheng@google.com>
1 file changed