Add Nexus 7 2013 (Flo) to EV Official

The following repos need forking to Evervolv org
https://github.com/EV-staging/android_device_asus_flo
https://github.com/EV-staging/proprietary_vendor_asus

Change-Id: I25ffcfb5141eaaaf39e9baf6f45cb30983739ddd