After the Zenfone Zoom and Zenfone 2 Laser, Asus has now started rolling out an update to its ZenFone 2 (ZE551ML) smartphone. The update is aimed at improving system stability, although no official release notes have been posted yet.Rolling out over the air, the update - which weighs in at around 103MB - may take some time before it hits your handset. However, if you are feeling impatient, you