title: "Package file was not signed correctly" error when Android app auto-updates
body: <p>Android (4.3) notifications show that several apps are attempting to auto-update but all are failing with an error saying "Package file was not signed correctly".  This happens repeated (over several days) for several apps.</p>
  
  <p>Possibly related: I installed a newer ROM (4.4) after doing a factory reset and then reverted to 4.3 from a nandroid backup. The problem noted here seemed to start after reverting the ROM.</p>