If you must keep using this version of Google Account Manager:
Google Account Manager 5.1-1743759 is specifically designed to work with Android 5.0 devices. This version of the app is optimized to take advantage of the new features and security enhancements in Android 5.0. Some of the benefits of using Google Account Manager 5.1-1743759 on Android 5.0 include: Google Account Manager 5.1-1743759 -Android 5.0
Before proceeding, on your Android 5.0 device: If you must keep using this version of