refactor: TetherIngress becomes TetherDownstream6 (and friends) am: 770e0a7a8f

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/1554238

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I70ec2e2e05ce4b2d10c62409fae2f98776c2d75e
tree: d5b63d8bd0e3e92898f22901214142feb27d8c98
  1. framework/
  2. tests/
  3. Tethering/
  4. .gitignore
  5. OWNERS
  6. PREUPLOAD.cfg
  7. TEST_MAPPING