Add NetworkStackConstants to framework/ am: ef5de53830

Original change: https://android-review.googlesource.com/c/platform/frameworks/libs/net/+/1512756

Change-Id: I294d9dd8a4b451dd0de5f1d6e211e4ab61fc7d80
tree: 9d653ce5b1cd12e4bf08789bd7d97b4881c65264
  1. staticlibs/