Update windows bleeding-edge git to 2.16.2

Bug: 811681
Change-Id: Id7b276274ba6e2e52fba9a19e6c15d5fd972c178
Reviewed-on: https://chromium-review.googlesource.com/919530
Commit-Queue: Aaron Gable <agable@chromium.org>
Reviewed-by: Robbie Iannucci <iannucci@chromium.org>

bootstrap/win/manifest_bleeding_edge.txt

@@ -17,4 +17,4 @@ $VerifiedPlatform windows-386 windows-amd64
 infra/python/cpython/${platform} version:2.7.13.chromium7
 
 @Subdir git
-infra/git/windows-${arch} version:2.15.1.2.chromium12
+infra/git/windows-${arch} version:2.16.2.chromium12