In some cases (e.g. in a CI system), it's desirable to be able to
instruct repo to force checkout. This flag passes --force flag to `git
checkout` operations.
Bug: b/327624021
Change-Id: I579edda546fb8147c4e1a267e2605fcf6e597421
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/411518
Commit-Queue: Josip Sokcevic <sokcevic@google.com>
Reviewed-by: Gavin Mak <gavinmak@google.com>
Reviewed-by: George Engelbrecht <engeg@google.com>
Tested-by: Josip Sokcevic <sokcevic@google.com>