Notification icon should be available in proper style for all Android platforms

[kaloyan-raev]

Currently, the status bar notification icons follow the design for ICS (Android 4.x). However, it does not look well on devices running an older version of the platform. The icons should be available in the proper style for all of the supported version of the platform.

http://developer.android.com/guide/practices/ui_guidelines/icon_design_status_bar.html
http://developer.android.com/design/style/iconography.html