Merge "Move utils from network stack to libs." am: f97ac209c2 am: d96c683595 am: 493f8b7b69 am: 4a4a60da0c

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1350083

Change-Id: I91978c34aa86b30969fdb90e57c1edd862a53a51
tree: 5ec0fb5d4e1c9a35c7f1def392befa98d54a9113
  1. Tethering/