Revive test-scap-backport deploy container script
Previously test-scap-backport contained the full code for testing scap backport. That code was eventually converted to Python and included in the scap source code and test-scap-backport was removed from train-dev.
This commit adds the test-scap-backport script back to the deploy container to make it easy to invoke the integration test in the scap repo.
Change-Id: Ib00f7960050fc048608694432cdffc55043878de