For package installs we need to be able to fix up permissions in
/var/log at install time, and if we delete all of the files then
those permission fixes get lost. To deal with that, we can just
empty the files instead of deleting them.
Change-Id: I70abb354e4dc726ec7a176694c7c6e9455d89d08
diskimage-builder/elements/base/cleanup.d/99-tidy-logs added
to tidy up (remove) initial logs files on disk images.
Makes for slightly smaller images, and easier times tracing post
boot issues.
Change-Id: Iee98b5d818e080bcd9635482bc29349a71938087