As with the previous similar changes, this is intended to catch
problems as they happen instead of ignoring them and continuing on
to potentially fail later. Setting this on all existing scripts
will allow us to enforce use via Jenkins.
Change-Id: Iad2d490c86dceab148ea9ab08f457c49a5d5352e
dib-init-system script is installed into $PATH. Called
without arguments it will print the name of init system
used to stdout.
Additionally, set DIB_INIT_SYSTEM environment variable to
the init system used.
Tested on ubuntu+upstart, centos+upstart, fedora+systemd,
debian+sysv.
Closes-Bug: #1251610
Change-Id: I29668079091f6060dab66d8259890384d3bbd653