Restore image status to 'queued' if upload failed

In v2, we're removing 'killed' status so as to let user
can retry upload if there is a failure. But based on
current implement, the image will be stuck in 'saving'
status when upload failed. This fix will restore the
image status to 'queued' to avoid the issue.

Closes-Bug: #1273087

Change-Id: Icd318e3e8d90b6837c84666c47f720b93febe228
Merge "Restore image status to 'queued' if upload failed"