Commit messages are now sent to input_api in the exact format that user
has used

Bug: angleproject:4714
Change-Id: I30592aec75d57618f5c028bb63a18f95239976e0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2239039Reviewed-by: Edward Lesmes <ehmaldonado@chromium.org>
Commit-Queue: Manh Nguyen <nguyenmh@google.com>