am ff3362f0: (-s ours) Merge "DO NOT MERGE - [ActivityManager] Ensure consistency behavior when a background activity brings another existed activity to front."

* commit 'ff3362f0d8378d616f39cbcf8b86b6f03e7d30b9':
  DO NOT MERGE - [ActivityManager] Ensure consistency behavior when a background activity brings another existed activity to front.