Merge "Move Tether4Key and Tether4Value to common libs" am: 34e16b9537 am: 958d7af11b am: 39f97d5b5c

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/1978067

Change-Id: Ia9f324251d12253c055c753f653465a8762b379c