BuildApi: api/controller/BundleDebugSymbols -- fix build_target param.

BUG=chromium:1031380
TEST=./run_pytest api/controller/artifacts_unittest.py

Change-Id: Idb93507ae1855d4c2dd638e86d6cd820e6497f01
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/2744790
Commit-Queue: Michael Mortensen <mmortensen@google.com>
Tested-by: Michael Mortensen <mmortensen@google.com>
Reviewed-by: Alex Klein <saklein@chromium.org>
diff --git a/api/controller/artifacts.py b/api/controller/artifacts.py
index 6ae23b4..609b2f7 100644
--- a/api/controller/artifacts.py
+++ b/api/controller/artifacts.py
@@ -678,12 +678,12 @@
     output_proto (BundleResponse): The output proto.
     _config (api_config.ApiConfig): The API call config.
   """
-  target = input_proto.build_target.name
   output_dir = input_proto.output_dir
 
   chroot = controller_util.ParseChroot(input_proto.chroot)
+  build_target = controller_util.ParseBuildTarget(input_proto.build_target)
   result = artifacts.GenerateBreakpadSymbols(chroot,
-                                             target,
+                                             build_target,
                                              debug=True)
 
   # Verify breakpad symbol generation before gathering the sym files.
@@ -691,7 +691,8 @@
     return controller.RETURN_CODE_COMPLETED_UNSUCCESSFULLY
 
   with chroot.tempdir() as symbol_tmpdir, chroot.tempdir() as dest_tmpdir:
-    breakpad_dir = os.path.join('/build', target, 'usr/lib/debug/breakpad')
+    breakpad_dir = os.path.join('/build', build_target.name,
+                                'usr/lib/debug/breakpad')
     sym_file_list = artifacts.GatherSymbolFiles(tempdir=symbol_tmpdir,
                                                 destdir=dest_tmpdir,
                                                 paths=[breakpad_dir])