There are several cases where we could pre-emptively extract pak files to improve start up time, including:
  * After clearing package data
  * After updates/installs
  * After language changes
  * After boot

There are broadcast receivers for all of these, but only ACTION_MY_PACKAGE_REPLACED is available for O+, so we'll need to use another approach. 

One approach is to use Background Task Scheduler to periodically check if we need to extract pak files and kick off extraction when necessary. It isn't perfect; we aren't actually listening for the events so we might end up missing opportunities to pre-extract these files but it's still more performant than the current setup.