By default, ubuntu trusty images has python3 executable in
path, but we can't use that for executing loguserdata script,
because pkg_resources can't be imported. Now it's proposed to
try importing pkg_resources for validating readiness of
python3 for executing this script. If pkg_resources can't be
imported there is no other choice except using python2.
Change-Id: Icb4f58630016874eb40dd77590469fc5de6287e4
Closes-bug: 1617069