Tweak the build process and and fix local container builds

We no longer distribute the blubber binary so the script to build
containers locally required some alteration to use blubber as a docker
buildkit frontend.

In addition we start to use the new version of blubber.

Bug: T303381
Change-Id: I5eb8b52e8fc40c32300427eb4e55f849f68b9d18