This specific version was released during the Android 5.0 era, which introduced the language and the Android Runtime (ART) . Google Account Manager was critical during this period for:
Ensure you have sufficient storage space and that you aren't attempting to install a version newer than what your OS supports. Google Account Manager 5.1-1743759 (Android 5.0+) Google Account Manager 5.1-1743759 -Android 5.0
: Ensuring that only the original owner can bypass security screens after a device wipe. Common Use Cases & "FRP Bypass" This specific version was released during the Android 5