EthernetTetheringTest needs to parse BPF map content for bpf stats
tests. Move the struct class files to common libs.
Compare TetherStats{Key, Value}.java between frameworks/libs/net/common
and packages/modules/Connectivity/Tethering.
There is only the package name change as expected.
$ diff packages/modules/Connectivity/Tethering/src/com/android/networkstack/tethering/TetherStatsKey.java frameworks/libs/net/common/device/com/android/net/module/util/bpf/TetherStatsKey.java
17c17
< package com.android.networkstack.tethering;
Bug: 227159997
Test: atest TetheringCoverageTests
Change-Id: I87193cb6409b4d19c72184011d7e99275800dab1
87bb6c3603