Update sync progress

repo sync progress bar is misleading. Many bug reports mentioned that
repo is stuck at the repo that is currently displayed in the progress
bar. Repo sync actually shows what repository is the last processed.
This change makes that obvious.

Change-Id: I962bf0bc65af7ac0ed98db86e9144f07d9e1f96f
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/357134
Reviewed-by: Joanna Wang <jojwang@google.com>
Tested-by: Josip Sokcevic <sokcevic@google.com>

subcmds/sync.py

@@ -544,7 +544,7 @@ later is required to fix a server side protocol bug.
             ret = False
           else:
             fetched.add(project.gitdir)
-          pm.update(msg=project.name)
+          pm.update(msg=f'Last synced: {project.name}')
         if not ret and opt.fail_fast:
           break
       return ret