run-test build: Explicitly call generate-sources

Let the scripts explicitly call it rather than making it
part of the build system magic.

It is much easier now with the context object.

Do not spam build log output with non-error messages.

Test: Generated artifacts are the same
Change-Id: I03b1e317b4f542c27b635ddd9defdd5c0e2bcb3e
39 files changed