Revert "Revert "New fixture to handle delta model snapshot""

This reverts commit 2fa3e1e2b706a398614103ddc97b25e8e140fb97.

Reason for revert: Fixed the post-submit issue

Bug: N/A
Test: see original commit
Change-Id: Ie5e7235054a4c0bf27b27d5fc02702b44b7f5e4c
51 files changed