There was a small issue in the recent change to perform system updates
when building the python-builder and python-base images. I didn't
realize that python-builder is a two stage build and we need to do the
update in both stages.
Ultimately this has minimal impact on the final images we produce as
those are all build on python-base not python-builder. But to ensure
some difference during python wheel build time on builder doesn't affect
the install location on the base image we should keep these in sync.
Change-Id: I16159fbb490b0ec2e179381a50b9570c9aacd18f
dd48296edd