Fix b/265632782: Battery usage app list changed when entering the app details page and back

This only happens on the first time the Settings package is installed.
Discussed with Chaohui, the old showSystemApp() logic in Settings->Apps has some issues. This cl updates the logic to the new logic Chaohui provided.

Bug: 265632782
Fix: 265632782
Test: manual
Change-Id: Iff5838f0299aed1b0ba2164b97e7fbdeefcadbee