title: Kivy on Android : keep local storage files after app updates
body: <p>I've got an Android app written in Kivy (Python), which stores local files that should survive an app update (adb install -r).</p>
  
  <p>If the files are stored in a subdirectory of the current directory ("data/data/app_name/files"), I see that they are deleted after update.</p>
  
  <p>However after some experiments I could "solve" this by storing the files in the "data/data/app_name/shared_prefs" directory, which seems to be persistent after updates. By the way, I didn't check but maybe the "data/data/app_name/databases" also is.</p>
  
  <p>Is there a cleaner way of doing things ?
  I need to test if I can create a new folder not called shared_prefs nor databases under "data/data/app_name", and if it is persistent.</p>
  
  <p>(this seems kind of a hack because those directories have another dedicated purpose, even though my app is not using them for this dedicated purpose right now)
  (NB: I don't want to keep the files outside the app private directory)</p>