change service container builder to just call the script

This pushes all logic into there, and means this file will not longer
need to be updated everytime an owner adds a new lib to build.
Additionally, pushing the logic into the build script allows for better
optimizations on cloud vs local builds, etc.

BUG=None
TEST=cq dry run (verified containers built there), cq, and unittest

Change-Id: I09c49d35ad70e813e572ec5dab977c03ca925059
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/3636803
Reviewed-by: Jaques Clapauch <jaquesc@google.com>
Commit-Queue: Jaques Clapauch <jaquesc@google.com>
Tested-by: Derek Beckett <dbeckett@chromium.org>
Auto-Submit: Derek Beckett <dbeckett@chromium.org>
Commit-Queue: Derek Beckett <dbeckett@chromium.org>
diff --git a/api/controller/test_unittest.py b/api/controller/test_unittest.py
index 2138370..b99021c 100644
--- a/api/controller/test_unittest.py
+++ b/api/controller/test_unittest.py
@@ -417,6 +417,7 @@
     patch.assert_called()
     for result in response.results:
       self.assertEqual(result.WhichOneof('result'), 'failure')
+      self.assertEqual(result.name, 'Service Builder')
 
 class ChromiteUnitTestTest(cros_test_lib.MockTestCase,
                            api_config.ApiConfigMixin):