Copy libcore.utils.HexEncoding into Wifi module

@CorePlatformApi's cannot be depended on by Wifi
Mainline module. Thus create a copy and migrate
usages over.

Bug: 145409537
Test: atest FrameworksWifiTests
Change-Id: I17eda020f10026c000e78f9df9cd569614374caa
10 files changed
tree: d898724e15a833cb047ab35a3be0fed28a6d3528
  1. apex/
  2. service/
  3. PREUPLOAD.cfg