Android will now launch notifications to alert you of new Google account sign-ins
These are Google's new Android security notifications
Those of you who've ever signed in to their Google account from a new device are probably well aware of Google's current account log-in security measures. When you (or someone else) log into your Google account from a new device, Google will send an email to your Gmail account informing you that a new sign-in has been detected.
By instantly launching a native Android notification when someone logs into their Google account from a non-recognized device, users are almost immediately warned that their log-in credentials might have been compromised. In tests, Google found that users are up to four times more likely to review the information from an Android notification as opposed to the older email notification system.
Google says that, if the user finds this log-in to be suspicious, pressing the "Review Account Activity" button will display a range of additional details, such as the name of the new device, its location, and other important information. If the notification was triggered by an expected activity, users can quickly dismiss the notification and be done with it.
source: Google
Things that are NOT allowed: