Merge "Add action for Bluetooth tethering state changed" am: cf44a015e8 am: 773810d198 am: f03a18b7ab

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1422889

Change-Id: Ibea11e73a0843785f790eb5a781a1ce3f7646c85