Previously we use /tmp inside horizon container to store temporal files
for image upload via Horizon, but this makes the image size grow for
each upload operation.
This patch makes sure that we use host directory to store temporal
file, so that it is not written inside container.
(cherry picked from commit a75cc9a9539bc8d6367f5771325914f15593e422)
(cherry picked from commit 12ad0d83a4fbb1a6de92750dba1bae8dbd4bf22a)