Applied code review changes.

Author: Isira-Seneviratne

app/src/main/java/org/schabi/newpipe/player/notification/NotificationConstants.java

@@ -180,7 +180,7 @@ public static List<Integer> getCompactSlotsFromPreferences(
 
             if (compactSlot == Integer.MAX_VALUE) {
                 // settings not yet populated, return default values
-                return SLOT_COMPACT_DEFAULTS;
+                return new ArrayList<>(SLOT_COMPACT_DEFAULTS);
             }
 
             // a negative value (-1) is set when the user does not want a particular compact slot

app/src/main/java/org/schabi/newpipe/player/notification/NotificationUtil.java

@@ -99,7 +99,7 @@ private synchronized NotificationCompat.Builder createNotification() {
         // build the compact slot indices array (need code to convert from Integer... because Java)
         final List<Integer> compactSlotList = NotificationConstants.getCompactSlotsFromPreferences(
                 player.getContext(), player.getPrefs(), nonNothingSlotCount);
-        final int[] compactSlots = compactSlotList.stream().mapToInt(i -> i).toArray();
+        final int[] compactSlots = compactSlotList.stream().mapToInt(Integer::intValue).toArray();
 
         builder.setStyle(new androidx.media.app.NotificationCompat.MediaStyle()
                     .setMediaSession(player.getMediaSessionManager().getSessionToken())

app/src/main/java/org/schabi/newpipe/settings/custom/NotificationActionsPreference.java

@@ -34,7 +34,6 @@
 import org.schabi.newpipe.util.ThemeHelper;
 import org.schabi.newpipe.views.FocusOverlayView;
 
-import java.util.ArrayList;
 import java.util.List;
 import java.util.stream.IntStream;
 
@@ -76,9 +75,10 @@ public void onDetached() {
     ////////////////////////////////////////////////////////////////////////////
 
     private void setupActions(@NonNull final View view) {
-        compactSlots = new ArrayList<>(NotificationConstants
-                .getCompactSlotsFromPreferences(getContext(), getSharedPreferences(), 5));
-        notificationSlots = IntStream.range(0, 5).mapToObj(i -> new NotificationSlot(i, view))
+        compactSlots = NotificationConstants.getCompactSlotsFromPreferences(getContext(),
+                getSharedPreferences(), 5);
+        notificationSlots = IntStream.range(0, 5)
+                .mapToObj(i -> new NotificationSlot(i, view))
                 .toArray(NotificationSlot[]::new);
     }