Comment 1 for bug 1515344

Independently if the notification is originated in our messaging app or Telegram or any other 3rd party messaging app, the expected behaviour is for the notification to lighten up the screen. Once the display is active, user can interact with the notification bubbles. See the Authentification section in the Notification System specification: https://docs.google.com/document/d/1xDSZ_dnAMAlhgFnnyjJEibaITXjVLp1_pnj_tATNm9I/edit#heading=h.btcq5d9yqfn9

Also, refer to the Screen blanking policy (https://docs.google.com/document/d/1RBoVknCLZ4GQ8E_iVftd3i_KmdxI5d6JrBt7i5EDZO0/edit# . On an idle phone, an incoming notification or system event such as an alarm or incoming call, will unblank the screen for the length of time of the notification or incoming call ringing time. If no user interaction takes place, the screen switches off automatically after the short timeout.