upload: include the project in error messages
upload: include the project in error messages

When running upload across multiple projects, include the project in
any error messages that come up.  This lets users figure out where
the problem might be.

Change-Id: I09470c9a1b512baf910d6d97b747816d1a6f3a87
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/304783
Reviewed-by: Raman Tenneti <66788d848ab03efc83371cd4b586a3110f9172ef@google.com>
Tested-by: Mike Frysinger <8f3f75c74bd5184edcfa6534cab3c13a00a2f794@google.com>

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