Add a bash completion "--force-sync" for repo sync

The new version v1.12.25 of repo add a new flas "--force-sync"
This will add the bash completion of the flag

Change-Id: I96700a1f13e6c5e1c361c48a4b778b4e7bc5dfed

bash_completion/repo.bash

@@ -587,6 +587,7 @@ _repo_sync() {
     OPTIONS=(
         "-h" "--help"
         "-f" "--force-broken"
+             "--force-sync"
         "-l" "--local-only"
         "-n" "--network-only"
         "-d" "--detach"