Move utils from network stack to libs.

This package is using some common utilities from
a library that used to live in the network stack.
A better home for these utilities is frameworks/libs,
so this topic moves the files ther and also changes
the package of some utilities.

See aosp/1350222 and aosp/1350182 for a detailed
description of the specific files that moved.

Test: checkbuild
Change-Id: I76a9b7790f3997e3e6b3c2f75ba6308286457cde