Do not checkout skia from chromium.googlesource.com in RecreateSKPs bot

It appears to be confusing "git cl upload".

BUG=skia:6033

Change-Id: I9813798dbfbbdb9eba6f4159f07e040ac865006c
Reviewed-on: https://skia-review.googlesource.com/5601
Reviewed-by: Eric Boren <borenet@google.com>
Commit-Queue: Ravi Mistry <rmistry@google.com>
tree: e8604bbe4f17137f2d314043625d90e42c5d7323
  1. recipe_modules/
  2. recipes.py
  3. recipes/