Add required permissions and files for data

 - Add /data/radio
 - Set gateway property after DNS
 - Allow radio users to set properties associated with
   all rmnet interfaces. Not just rmnet0

Change-Id: Ia60fcb8f90aa73ffd40e839b93356ee50a9e5072
init.rc: Restored TCP performance tuning

This patch tunes the TCP buffer sizes for high
performance data links including global max rmem
and wmem.

Change-Id: I78dc92bc8190883686678230b0a34a8e32507fa5
CRs-Fixed: 439205 435908

Conflicts:
	rootdir/init.rc