BuildTargetUnitTest: Only use package atoms, not cpf.

The unittest script only accepts atoms. Discard the version when
it is given.

BUG=chromium:1130818
TEST=./run_pytest

Change-Id: I5ecc7441c7027eae01c216a1f48c91b5a755b6f1
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/2424786
Commit-Queue: Alex Klein <saklein@chromium.org>
Tested-by: Alex Klein <saklein@chromium.org>
Reviewed-by: Navil Perez <navil@google.com>
Reviewed-by: Michael Mortensen <mmortensen@google.com>
diff --git a/api/controller/test.py b/api/controller/test.py
index 5f6aa4b..59c6587 100644
--- a/api/controller/test.py
+++ b/api/controller/test.py
@@ -76,8 +76,9 @@
 
 @faux.success(_BuildTargetUnitTestResponse)
 @faux.error(_BuildTargetUnitTestFailedResponse)
-@validate.require('build_target.name', 'result_path')
+@validate.require('build_target.name')
 @validate.exists('result_path')
+@validate.require_each('packages', ['category', 'package_name'])
 @validate.validation_complete
 @metrics.collect_metrics
 def BuildTargetUnitTest(input_proto, output_proto, _config):
@@ -94,7 +95,8 @@
   packages_package_info = input_proto.packages
   packages = []
   for package_info_msg in packages_package_info:
-    packages.append(controller_util.PackageInfoToString(package_info_msg))
+    cpv = controller_util.PackageInfoToCPV(package_info_msg)
+    packages.append(cpv.cp)
 
   # Skipped tests.
   # TODO: Remove blacklist when we fully switch to blocklist.