t30-common: enable 3G for A701

Based on work by mrzottel

On the A700, ro.boot.carrier will be set to wifi-only. Based on that,
we will
 - Remove unneeded files at install time using releasetools
 - Disable telephony services at runtime using init.target.rc

Change-Id: Ib17aefc94b1619efb143441fcf63a725539efff1