Merge "Move utils from network stack to libs." am: f97ac209c2

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

Change-Id: I846dae9b7e36ddf6360bb946cc07beb8c44a34a5
tree: 088061007adc26712a03102ddad37d9ca8ec7396
  1. Tethering/