According to "code conventions" [1], do not use "-y" option.
Instead, use apt-get install package, yum install package,
or zypper install package.
[1] https://docs.openstack.org/doc-contrib-guide/writing-style/
code-conventions.html
Change-Id: Ib64fd1f1774ff3f3e3fa5318e2fbe5d9f92d21fc