[Android] Fix return code for Sharded Perf step.

build/android/test_runner.py

Index: build/android/test_runner.py
diff --git a/build/android/test_runner.py b/build/android/test_runner.py
index faec49217dab98fca50c2c394830493038196edb..7a14a7166735dffa60f5f91610d76ac0e9f34840 100755
--- a/build/android/test_runner.py
+++ b/build/android/test_runner.py
@@ -933,6 +933,9 @@ def RunTestsInPlatformMode(args):
           json_results.GenerateJsonResultsFile(
               all_raw_results, args.json_results_file)
 
+  if args.command == 'perf' and (args.steps or args.single_step):
+    return 0
+
   return (0 if all(r.DidRunPass() for r in all_iteration_results)
           else constants.ERROR_EXIT_CODE)