api: Drop unit_tests.tar generation function.

Drop the ability to generate unit_tests.tar from the
ArtifactService/Get endpoint. Drop the unit_tests.tar generation
from service/ all together since it is unused.

BUG=b:187784525, b:217211026
TEST=CQ

Change-Id: I64c3ff769a46f4d784045cd0daf2938863fe9cfa
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/3444504
Tested-by: Alex Klein <saklein@chromium.org>
Reviewed-by: George Engelbrecht <engeg@google.com>
Commit-Queue: Alex Klein <saklein@chromium.org>
diff --git a/api/controller/test_unittest.py b/api/controller/test_unittest.py
index 2ac2868..d8e0e0c 100644
--- a/api/controller/test_unittest.py
+++ b/api/controller/test_unittest.py
@@ -715,8 +715,6 @@
 
   CODE_COVERAGE_LLVM_ARTIFACT_TYPE = (
       common_pb2.ArtifactsByService.Test.ArtifactType.CODE_COVERAGE_LLVM_JSON)
-  UNIT_TEST_ARTIFACT_TYPE = (
-      common_pb2.ArtifactsByService.Test.ArtifactType.UNIT_TESTS)
 
   def setUp(self):
     """Set up the class for tests."""
@@ -767,17 +765,11 @@
     """Test result contains paths and code_coverage_llvm_json type."""
     self.PatchObject(
         test_service, 'BundleCodeCoverageLlvmJson', return_value='test')
-    self.PatchObject(
-        test_service,
-        'BuildTargetUnitTestTarball',
-        return_value='unit_tests.tar')
 
     result = test_controller.GetArtifacts(
         common_pb2.ArtifactsByService.Test(output_artifacts=[
             # Valid
             common_pb2.ArtifactsByService.Test.ArtifactInfo(
-                artifact_types=[self.UNIT_TEST_ARTIFACT_TYPE]),
-            common_pb2.ArtifactsByService.Test.ArtifactInfo(
                 artifact_types=[self.CODE_COVERAGE_LLVM_ARTIFACT_TYPE]),
         ]),
         self.chroot,
@@ -785,7 +777,5 @@
         self.build_target,
         self.tempdir)
 
-    self.assertEqual(result[0]['paths'], ['unit_tests.tar'])
-    self.assertEqual(result[0]['type'], self.UNIT_TEST_ARTIFACT_TYPE)
-    self.assertEqual(result[1]['paths'], ['test'])
-    self.assertEqual(result[1]['type'], self.CODE_COVERAGE_LLVM_ARTIFACT_TYPE)
+    self.assertEqual(result[0]['paths'], ['test'])
+    self.assertEqual(result[0]['type'], self.CODE_COVERAGE_LLVM_ARTIFACT_TYPE)