Also fixes related issue with distutils installation for Debian Stretch
and Ubuntu Xenial with py3: unlike in Bionic, distutils is installed with
python3 and python3-distutils package is not available in these distributions.
Run Debian build with py3 against stable/train, as master requires at
least python3.6, not available for distribution out of box.
Also increases job timeout to 5400 due to increased amount of builds.
Change-Id: I04c9253af80d941afb45231bee20f7bb1c4a96d4
3e5730cd53