sync: Handle KeyboardInterrupt during checkout

KeyboardInterrupt is handled during NetworkHalf. This patch handles
KeyboardInterrupt during LocalHalf.

Bug: b/372069163
Change-Id: I26847f7ca3cdf1fe57b265b4f6b18cc8102d2921
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/447401


Tested-by: Josip Sokcevic <sokcevic@chromium.org>
Reviewed-by: Gavin Mak <gavinmak@google.com>