title: Upgrade remains till the time phone is rebooted
body: <p>I have an application, which I have made it as part of system apps.
  I have an option to sideload the application and upgrade to next level and upgrade works fine.
  But, when I reboot the device, Android points back to the system app and the upgrade is lost.</p>
  
  <p>Any pointers on how to resolve this problem?</p>