am ff025412: Merge "Revert "Revert "Upload screennails in tiles to prevent jank""" into gb-ub-photos-arches

* commit 'ff025412e2cacedd8cbb7901140e580f76634ee6':
  Revert "Revert "Upload screennails in tiles to prevent jank""
tree: c859a690588784e94aeccb20fd29c698188cc44a
  1. gallerycommon/
  2. src/
  3. src_pd/
  4. tests/