[snapshots] Update Snapshot Builder to Xenial

Bug: 966276
Change-Id: I347386b75c3f595050248f33993fc48f893ef2bf
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1626808
Reviewed-by: John Budorick <jbudorick@chromium.org>
Reviewed-by: Andrii Shyshkalov <tandrii@chromium.org>
Commit-Queue: smut <smut@google.com>
Cr-Commit-Position: refs/heads/master@{#662847}
1 file changed