When a repo has both staged and unstaged changes for a same file, `git
freeze` doesn't work as intended. It freezes only the indexed changes
and has to be run twice to achieve the intended results. This change
fixes this case.
Change-Id: Ie620a111c4a6f721bf6c85200cb05676022041a1
Bug: 1476516
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/4820460
Reviewed-by: Gavin Mak <gavinmak@google.com>
Commit-Queue: Aravind Vasudevan <aravindvasudev@google.com>