[Umpire] make it able to import release image from CPFE directly

An image from CPFE or GoldenEye is a complete image that contains
stateful partition, kernel-a, rootfs-a, kernel-b, rootfs-b, EFI, etc.
But due to historical reason, mini-omaha needs a different format.

This CL converts the complete image to mini-omaha format before
importing it, makes the user able to import an image from CPFE or
GoldenEye directly,

TEST=make test

Change-Id: I393093415943c61f0986982b4baeaa3447e5500a
Reviewed-on: https://chromium-review.googlesource.com/332312
Commit-Ready: Mao Huang <littlecvr@chromium.org>
Tested-by: Mao Huang <littlecvr@chromium.org>
Reviewed-by: Rong Chang <rongchang@chromium.org>
3 files changed