controller_util.CPVToPackageInfo: Refactor last usages

BUG=b:187792048
TEST=run_tests, cq

Change-Id: I781f9d5dd5add2e6ed544c432a4b9f0286a6eb75
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/3152624
Tested-by: Alex Klein <saklein@chromium.org>
Reviewed-by: Chris McDonald <cjmcdonald@chromium.org>
Reviewed-by: Sergey Frolov <sfrolov@google.com>
Commit-Queue: Alex Klein <saklein@chromium.org>
diff --git a/api/controller/sysroot_unittest.py b/api/controller/sysroot_unittest.py
index a9e7544..9115eb1 100644
--- a/api/controller/sysroot_unittest.py
+++ b/api/controller/sysroot_unittest.py
@@ -404,9 +404,9 @@
       instance.package_indexes.extend(package_indexes)
     if packages:
       for pkg in packages:
-        pkg_info = instance.packages.add()
-        cpv = package_info.SplitCPV(pkg, strict=False)
-        controller_util.CPVToPackageInfo(cpv, pkg_info)
+        pkg_info = package_info.parse(pkg)
+        pkg_info_msg = instance.packages.add()
+        controller_util.serialize_package_info(pkg_info, pkg_info_msg)
     return instance
 
   def _OutputProto(self):