Clean up a build script

- Pin down the version of the cos-kernel-devenv container
- Only upload to the GS bucket if both builds are successfull
  to avoid partially valid artifacts
- Add kernel_commit file to pass down to COS image build
- Remove debug output from the early development stage
- Fix glint warnings

BUG=b/204367125
TEST=presubmit
RELEASE_NOTE=None

Change-Id: I1b43bed9c04784b5a2a702b4a2aa8513904af686
Reviewed-on: https://cos-review.googlesource.com/c/third_party/kernel/+/27280
Reviewed-by: Meena Shanmugam <meenashanmugam@google.com>
Tested-by: Oleksandr Tymoshenko <ovt@google.com>
1 file changed