With Android Lollipop, Google brought heads-up notifications to Android and bid goodbye to notification tickers. Heads-up notifications are useful for quickly drawing attention to the notifications but it can be annoying when a notification suddenly covers up a portion of your screen while you’re watching a video or a movie. To solve this problem, a developer has come up with a new app named TinyNotif that brings back the good-old notification tickers on newer Android devices.
adb shell settings put global heads_up_notifications_enabled 0
In case you wish to revert the changes and enable heads-up notifications later, simply run the same command by replacing the 0 at the end by 1. You can use the DND mode to temporarily achieve the same but it comes at the cost of muting your phone.