Show the correct app list of a permission

The same app list is shown in the different permission-apps UIs,
since the same view model object was used within the same activity.

Fixed that each fragment uses own view model.

Bug: 297315110
Test: Settings > App & notifications > App permissions >
Additional permissions > Disable touch > back >
Read instant messages -> check if proper app list is visible

Change-Id: Iad53ce5f396f636d409c14597fdfc3e6dfbd478d