After you downloaded the new Android firmware Lollipop update to your Samsung Galaxy S4, you will perhaps notice after some testing a new icon in the status bar. This icon is in the shape of a star. If you notice that star in the notification bar of your Samsung Galaxy S4, then this has the following reason:
The star symbol stands in Android Lollipop for the interrupt mode. This mode was newly installed with Android lollipop on the Samsung Galaxy S4. This can be found and configured in the following submenu:
Home Screen --> Apps --> Settings -> My Device -> Sounds & Notifications -> interruptions
You can now specify when interruptions on your Samsung Galaxy S4 are allowed or desired. Have you set the settings, then the interrupt mode (star symbol) can be easily activated and also deactivated via the status bar. Draw the status bar with two fingers from the top of the screen. You will find a button with "only priority" (if active) or "Always interrupt" (when inactive).
In order to hide the star icon in the status bar, the interrupt mode must be set to "Always interrupt ".
You now know what the star icon on your Samsung Galaxy S4 with Android Lollipop means and how disable the interrupt mode and therefore to hide this star from the status bar.