Fix last resize mode not being restored correctly

I think the settings key "last_resize_mode" is ambiguous. While it is used to get the recently used resize mode, someone thought while working on the resize mode switcher, that the old (to be replaced) resize mode should be stored. 
Fixes #5613

app/src/main/java/org/schabi/newpipe/player/helper/PlayerHelper.java

@@ -484,8 +484,9 @@ public final class PlayerHelper {
                 break;
         }
 
+        // save the new resize mode so it can be restored in a future session
         player.getPrefs().edit().putInt(
-                player.getContext().getString(R.string.last_resize_mode), resizeMode).apply();
+                player.getContext().getString(R.string.last_resize_mode), newResizeMode).apply();
         return newResizeMode;
     }