git-review: add config file
git-review: add config file

This is used by the `git review` tool that some people use.

Change-Id: I8dac4e1dad155109a05181deaec61e1a74857b1f
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/323698
Reviewed-by: Raman Tenneti <66788d848ab03efc83371cd4b586a3110f9172ef@google.com>
Tested-by: Mike Frysinger <8f3f75c74bd5184edcfa6534cab3c13a00a2f794@google.com>

lewixliu/git-repo,GerritCodeReview/git-repo,couchbasedeps/git-repo,lewixliu/git-repo,couchbasedeps/git-repo,GerritCodeReview/git-repo