Get/Set IO capability of Bluetooth device

Creates the hidden BluetoothAdapter APIs which can be used to
control IO capability settings on the local Bluetooth device.

Bug: 36015413
Test: Used a test activity to control getting/setting the value and
attempting pairing.

Change-Id: Ibbfdc5ae5a1d56c6e3d003ab3bf5d095dcb583e4
(cherry picked from commit 6043b7b90a27a836241bfc05e71eb46ce04c66cf)