RHEL7 derived distros use Python 2.7
RHEL8 uses Python 3.6
Ubuntu 18.04 uses Python 3.6, but we haven't enabled it yet.
Debian:buster uses Python 3.7, but we haven't enabled it yet.
We have several places in code where "/lib/pythonX.Y/site-packages"
is used so we need to know value of X.Y rather than py2/py3 switch.
How to check for Python 2:
{% if distro_python_version == '2.7' %}
Breaks: Iad6b70b433a0dd1b0f8ae6790fd280594517661a
Change-Id: Ie24f109af19ae0438c21e0d43cb3cc947812b4ce