Show silent notification only when the device is unlocked

This change addresses an issue with the current silent notification, which shows KDE Connection status with Send Clipboard, Send Files, and Run Command buttons even when the device is locked.

It’s better to show these actions only after unlocking the device because: • A newer version of Android devices shows a bigger clock when there are no notifications. • After locking the device on lock wallpaper we can’t see the bigger clock. Because, this notification can't be clear and automatically appears always.

This change ensures that the silent notification is displayed only when the device is unlocked.