Merge "Add BluetoothDevice#connect and BluetoothDevice#disconnect as System APIs" into stage-aosp-master am: 4a39b54ec1 am: 0db21e73d3 am: 269e7b39db am: 2b19bbe94a

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/15936310

Change-Id: Ic3bbcd8f4bc6e1da07f5b5d58c4599f1f7b389f1