Remove use of sudo from yum pre and post elements

sudo is not needed, since in-chroot elements are run in the context
of the root user. Furthermore, sudo in pre-install is problematic as
sudo may not have been installed yet (imagine a debootstrap build)

Change-Id: Ib5c7e176a90fe3b8fa9c3cd702d3d815df54f472
Merge "Remove use of sudo from yum pre and post elements"