Google on Friday announced that it has begun to push out an update that will bring Android 4.0 Ice Cream Sandwich to its Nexus S smartphone. “We’re rolling out Android 4.0, Ice Cream Sandwich, to GSM/UMTS Nexus S devices over the coming month, starting today,” Google’s Android team wrote in a post on Google+. The Ice Cream Sandwich update is available over the air (OTA) for GSM Nexus S handsets and while the roll-out will begin today, Google indicated that it could take as long as a month to complete. The company did not indicate when Android 4.0 might become available for Sprint’s Nexus S 4G.