Bluetooth: advertising improvements

This patch removes isPeripheralModeSupported(), hidden public method
which is always returning true. It also modify the BluetoothLeAdvertiser
to be able to use advertising instance with instance id equal 0.

Bug: 30622771
Bug: 24099160
Change-Id: Id31582621dbe56d5c3a8d4ee5cd296af66a5f026
3 files changed