gce_au_worker: shorten the instance and image name prefixes

This patch primarily shortens the name of the GCE instance where the tests run,
so that the hostname is under HOST_NAME_MAX.  It also shortens the test image
name to remain consistent with the instance name.

TEST=None
BUG=None

Change-Id: Ibdbb3d1e76d3017a5fc289a0162fc434014e4fdd
Reviewed-on: https://chromium-review.googlesource.com/329982
Commit-Ready: Amey Deshpande <ameyd@google.com>
Tested-by: Amey Deshpande <ameyd@google.com>
Reviewed-by: Daniel Wang <wonderfly@google.com>
1 file changed