Merge "Reuse BluetoothPan object and use it under tethering handler thread" am: 5c4010e196 am: b823c10754

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

Change-Id: I03bea1e97c5eeecad0b1b74083c5080f6ce8594e