Update PGP keys during _PostRepoUpgrade in `sync`

Previously, if a key was added, a client wouldn't add the key during
the sync step.  This would cause issues if a new key were added and a
subsequent release were signed by that key.

Change-Id: I4fac317573cd9d0e8da62aa42e00faf08bfeb26c
diff --git a/subcmds/sync.py b/subcmds/sync.py
index a4ca344..a7df7c8 100644
--- a/subcmds/sync.py
+++ b/subcmds/sync.py
@@ -46,6 +46,7 @@
 
 from git_command import GIT
 from git_refs import R_HEADS, HEAD
+from main import WrapperModule
 from project import Project
 from project import RemoteSpec
 from command import Command, MirrorSafeCommand
@@ -537,7 +538,7 @@
     mp.PreSync()
 
     if opt.repo_upgraded:
-      _PostRepoUpgrade(self.manifest)
+      _PostRepoUpgrade(self.manifest, opt)
 
     if not opt.local_only:
       mp.Sync_NetworkHalf(quiet=opt.quiet,
@@ -611,7 +612,10 @@
     if self.manifest.notice:
       print self.manifest.notice
 
-def _PostRepoUpgrade(manifest):
+def _PostRepoUpgrade(manifest, opt):
+  wrapper = WrapperModule()
+  if wrapper.NeedSetupGnuPG():
+    wrapper.SetupGnuPG(opt.quiet)
   for project in manifest.projects.values():
     if project.Exists:
       project.PostRepoUpgrade()