Merge "Reuse BluetoothPan object and use it under tethering handler thread" am: 5c4010e196 am: b23e94c1a7

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/1908683

Change-Id: If513a637b3cbd31c7272f48553c79232831af97a