binhost controller: Cleanup parallel postsubmit binhost.

The Build API manually altered the binhost type to avoid
collisions with the legacy postsubmit builders. Remove the
hard-coded key change to have the Build API update the
standard file with a better name.

BUG=chromium:965244
TEST=run_tests

Change-Id: I4bc70394aecc6c71542efc2a7664c4fc25d9d4fb
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/1857011
Tested-by: Alex Klein <saklein@chromium.org>
Reviewed-by: David Burger <dburger@chromium.org>
Commit-Queue: Alex Klein <saklein@chromium.org>
diff --git a/api/controller/binhost_unittest.py b/api/controller/binhost_unittest.py
index aa034d9..61de3e1 100644
--- a/api/controller/binhost_unittest.py
+++ b/api/controller/binhost_unittest.py
@@ -97,8 +97,10 @@
 
     self.assertEqual(self.response.output_file, '/path/to/BINHOST.conf')
     set_binhost.assert_called_once_with(
-        'target', 'PARALLEL_POSTSUBMIT_BINHOST',
-        'gs://chromeos-prebuilt/target', private=True)
+        'target',
+        'POSTSUBMIT_BINHOST',
+        'gs://chromeos-prebuilt/target',
+        private=True)
 
 
 class RegenBuildCacheTest(cros_test_lib.MockTestCase,