update_engine: Add Squashfs (phase 2)

This patch replaces the Android container related Squashfs images with
their files in the update engine. The location of each new file is
defined as:
'Squashfs image file path' + / + 'the file path inside the Squashfs'

This works even if the files inside the Squashfs are not 4k aligned. But
we need 4k alignment before we add Puffin support. In some experiments
this could even reduce the delta payload size by like 1MB.

BUG=chromium:767120
TEST=cros_workon_make --board=amd64-generic --test update_engine; brillo_update_payload generate --payload=payload.delta --source_image=veyron_minnie-R61-9765.13.0.bin --target_image=veyron-minnie-R62-9804.0.0.bin

Change-Id: I3fbcc5cd0d724435955ed1bd1204dee0e41944be
Reviewed-on: https://chromium-review.googlesource.com/636106
Commit-Ready: Amin Hassani <ahassani@chromium.org>
Tested-by: Amin Hassani <ahassani@chromium.org>
Reviewed-by: Ben Chan <benchan@chromium.org>

0 files changed, 0 insertions, 0 deletions