create pngs for ic_install.xml and ic_notification_outlined.xml

On Kitkat the app would crash because it cannot handle xml drawables in the Notification area. So here I converted ic_install.xml and ic_notification_outlined.xml

commit message: create pngs for ic_install.xml and ic_notification_outlined.xml

convert pngs from xmls for Notification icons. They will be used on platforms prior sdk v21