public StatusBarNotification[] getActiveNotifications() throws RemoteException {
        Bundle notifications = mService.getActiveNotifications();
        return ActiveNotificationsArgs.fromBundle(notifications).notifications;
    }
Gets the notifications shown by the Trusted Web Activity client. Can only be called on
Android M and above.
@return Array of active notifications.
@throws RemoteException If the Service dies while responding to the request.
@throws SecurityException If verification with the TrustedWebActivityService fails.
@throws IllegalStateException If called on Android pre-M.
customtabs/src/android/support/customtabs/trusted/TrustedWebActivityServiceWrapper.java