Add Android O-related files to android-sdk-packager

Adds the necessary files and changes to start generating Android O x86
emulator system images.

Bug: 1145728
Change-Id: I31e4b56b70991b7850ac410655a085d84f0eb52c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2553025
Commit-Queue: Brian Sheedy <bsheedy@chromium.org>
Reviewed-by: Haiyang Pan <hypan@google.com>
Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Cr-Commit-Position: refs/heads/master@{#831986}
GitOrigin-RevId: 37b7dc1b01ee6f49ea53c6071102dd95433d377a