Fix the selected option not saved for App List

The available options will be refreshed each time the app list is
re-entered, which caused the selected option is cleared before.

Only reset the selected option if it is not available any more to fix
this issue.

Bug: 264228237
Test: Manually with Settings
Test: Unit test
Change-Id: I6d7b65d0a944bf1ab392500d17966c697971ea64