core: AsyncTaskType - uploadImageFromStream to uploadImageToStream

changed uploadImageFromStream to uploadImageToStream as appears on vdsm.

Change-Id: I42de0ddf13fba46c68674e20b570cd0ea759eff8
Bug-Url: https://bugzilla.redhat.com/1136840
Signed-off-by: Liron Aravot <laravot@redhat.com>