cos-dkms: Release cos-dkms v0.2.0

This adds the --insert-on-install flag and allows the reading of
environment variables from an lsb-release file. Additionally, this fixes
an issue with downloading from GCS buckets whose names have trailing
slashes.

BUG=b/389772265
TEST=cloudbuild and pre-release test
RELEASE_NOTE=Add --insert-on-install flag and improved default value handling to cos-dkms.

Change-Id: I47bd59391422729f0c74e85144570af6d5cd1756
Reviewed-on: https://cos-review.googlesource.com/c/cos/tools/+/90822
Cloud-Build: GCB Service account <228075978874@cloudbuild.gserviceaccount.com>
Reviewed-by: Arnav Kansal <rnv@google.com>
Tested-by: Kevin Berry <kpberry@google.com>

release/release-versions.yaml

diff --git a/release/release-versions.yaml b/release/release-versions.yaml
index 1898663..945ae65 100644
--- a/release/release-versions.yaml
+++ b/release/release-versions.yaml
@@ -35,7 +35,7 @@
     - "v0.1.2"
 - staging_container_name: "cos-dkms"
   release_container_name: "cos-dkms"
-  build_tag: "a4d96a4-1b92cefe-a05d-4659-8193-6e2d866c44c9"
+  build_tag: "f44fc88-450dc928-b704-4ba6-9710-487ba2eaf51b"
   release_tags:
     - "latest"
     - "v0.1.1"