[UX] Notification are displayed too short (#3962)

Changed from 1 second to 2.

I also fixed the problem with blocking the UI when displaying the message. Now notification box is closed after taping anywhere (like InfoMessage).

frontend/apps/reader/modules/readerfrontlight.lua

@@ -75,7 +75,7 @@ function ReaderFrontLight:onShowIntensity()
     end
     UIManager:show(Notification:new{
         text = new_text,
-        timeout = 1.0,
+        timeout = 2,
     })
     return true
 end