AppControl: Fix crash when passing 0 selected items from multi selection

[d4rken]

Via playconsole

Exception java.util.NoSuchElementException: List is empty.
  at kotlin.collections.CollectionsKt___CollectionsKt.single (CollectionsKt___Collections.kt:2)
  at eu.darken.sdmse.appcontrol.ui.list.AppControlListFragment$onViewCreated$$inlined$observe2$2.invoke (AppControlListFragment.java)
  at eu.darken.sdmse.appcontrol.ui.list.AppControlListFragment$onViewCreated$$inlined$observe2$2.invoke (AppControlListFragment.java)
  at androidx.lifecycle.LiveData.considerNotify (LiveData.java)
  at androidx.lifecycle.LiveData.dispatchingValue (LiveData.java)
  at androidx.lifecycle.MutableLiveData.setValue (MutableLiveData.java)
  at eu.darken.sdmse.common.SingleLiveEvent.setValue (SingleLiveEvent.java)
  at androidx.lifecycle.LiveData$1.run
  at android.os.Handler.handleCallback (Handler.java:938)
  at android.os.Handler.dispatchMessage (Handler.java:99)
  at android.os.Looper.loopOnce (Looper.java:210)
  at android.os.Looper.loop (Looper.java:299)
  at android.app.ActivityThread.main (ActivityThread.java:8319)
  at java.lang.reflect.Method.invoke
  at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run (RuntimeInit.java:556)
  at com.android.internal.os.ZygoteInit.main (ZygoteInit.java:1038)